diff --git a/doc/whats-new.rst b/doc/whats-new.rst
index 089cbbe1be3..4a6083522ba 100644
--- a/doc/whats-new.rst
+++ b/doc/whats-new.rst
@@ -71,6 +71,9 @@ Bug fixes
 
 Documentation
 ~~~~~~~~~~~~~
+- Fix documentation of :py:class:`DataArray` removing the deprecated mention
+  that when omitted, `dims` are inferred from a `coords`-dict. (:pull:`3821`)
+  By `Sander van Rijn <https://github.com/sjvrijn>`_.
 
 Internal Changes
 ~~~~~~~~~~~~~~~~
diff --git a/xarray/core/dataarray.py b/xarray/core/dataarray.py
index 062cc6342df..2f023d0c25c 100644
--- a/xarray/core/dataarray.py
+++ b/xarray/core/dataarray.py
@@ -1,6 +1,5 @@
 import datetime
 import functools
-import warnings
 from numbers import Number
 from typing import (
     TYPE_CHECKING,
@@ -304,8 +303,7 @@ def __init__(
             Name(s) of the data dimension(s). Must be either a hashable (only
             for 1D data) or a sequence of hashables with length equal to the
             number of dimensions. If this argument is omitted, dimension names
-            are taken from ``coords`` (if possible) and otherwise default to
-            ``['dim_0', ... 'dim_n']``.
+            default to ``['dim_0', ... 'dim_n']``.
         name : str or None, optional
             Name of this array.
         attrs : dict_like or None, optional
@@ -1860,7 +1858,7 @@ def to_unstacked_dataset(self, dim, level=0):
         # unstacked dataset
         return Dataset(data_dict)
 
-    def transpose(self, *dims: Hashable, transpose_coords: bool = None) -> "DataArray":
+    def transpose(self, *dims: Hashable, transpose_coords: bool = True) -> "DataArray":
         """Return a new DataArray object with transposed dimensions.
 
         Parameters
@@ -1868,7 +1866,7 @@ def transpose(self, *dims: Hashable, transpose_coords: bool = None) -> "DataArra
         *dims : hashable, optional
             By default, reverse the dimensions. Otherwise, reorder the
             dimensions to this order.
-        transpose_coords : boolean, optional
+        transpose_coords : boolean, default True
             If True, also transpose the coordinates of this DataArray.
 
         Returns
@@ -1897,15 +1895,6 @@ def transpose(self, *dims: Hashable, transpose_coords: bool = None) -> "DataArra
                 coords[name] = coord.variable.transpose(*coord_dims)
             return self._replace(variable, coords)
         else:
-            if transpose_coords is None and any(self[c].ndim > 1 for c in self.coords):
-                warnings.warn(
-                    "This DataArray contains multi-dimensional "
-                    "coordinates. In the future, these coordinates "
-                    "will be transposed as well unless you specify "
-                    "transpose_coords=False.",
-                    FutureWarning,
-                    stacklevel=2,
-                )
             return self._replace(variable)
 
     @property
diff --git a/xarray/core/groupby.py b/xarray/core/groupby.py
index f2a9ebac6eb..3c78882d5b8 100644
--- a/xarray/core/groupby.py
+++ b/xarray/core/groupby.py
@@ -292,7 +292,7 @@ def __init__(
         bins : array-like, optional
             If `bins` is specified, the groups will be discretized into the
             specified bins by `pandas.cut`.
-        restore_coord_dims : bool, optional
+        restore_coord_dims : bool, default True
             If True, also restore the dimension order of multi-dimensional
             coordinates.
         cut_kwargs : dict, optional
@@ -390,14 +390,6 @@ def __init__(
             and restore_coord_dims is None
             and any(obj[c].ndim > 1 for c in obj.coords)
         ):
-            warnings.warn(
-                "This DataArray contains multi-dimensional "
-                "coordinates. In the future, the dimension order "
-                "of these coordinates will be restored as well "
-                "unless you specify restore_coord_dims=False.",
-                FutureWarning,
-                stacklevel=2,
-            )
             restore_coord_dims = False
 
         # specification for the groupby operation
diff --git a/xarray/tests/test_dataarray.py b/xarray/tests/test_dataarray.py
index 0a622d279ba..3e5d8361bd1 100644
--- a/xarray/tests/test_dataarray.py
+++ b/xarray/tests/test_dataarray.py
@@ -2119,9 +2119,6 @@ def test_transpose(self):
         with pytest.raises(ValueError):
             da.transpose("x", "y")
 
-        with pytest.warns(FutureWarning):
-            da.transpose()
-
     def test_squeeze(self):
         assert_equal(self.dv.variable.squeeze(), self.dv.squeeze().variable)
 
@@ -2703,9 +2700,6 @@ def test_groupby_restore_coord_dims(self):
             )["c"]
             assert result.dims == expected_dims
 
-        with pytest.warns(FutureWarning):
-            array.groupby("x").map(lambda x: x.squeeze())
-
     def test_groupby_first_and_last(self):
         array = DataArray([1, 2, 3, 4, 5], dims="x")
         by = DataArray(["a"] * 2 + ["b"] * 3, dims="x", name="ab")