It can be done in MacOS and you can basically choose any key(combo) you want. However the standard behavior is the context menu triggers at the location of the mouse pointer, not the cursor. And thus the context menu does not contain the autocorrect functionality that you would want it to have.
So it is not per se an Obsidian issues, but while reading all the posts on the forum and on Discord, I never really saw somebody mention that it would not work on MacOS. 
Microsoft Word does not handle it in a nice way, it also creates a pop up at the mouse pointer location.
Apple Pages (their Word counter part) handles this particular issue in the follownig way:

And you can select the correct spelling pressing a Down Arrow, Enter sequence.
And firing the keycombo for the context menu gives:
The mouse was located at the topleft corner of where the context menu is located in the picture, but is was not included in the screenshot.
So MacOS can do this, although I am not entirely sure Apple opened this up for non-Apple applications.
Edit: further experimentation learns that this popup behavior seems not to be fully consistent.