Yes, but OS/2 2.0 was not going to be released in 1990 either so it would be stupid to abandon Windows 3.x immediately anyway. And as I mentioned in the comments, nothing prevents the two from coexisting for a few years with OS/2 2.x being compatible with Win3.x.
Win3.x (OS/2 2.x would be able to run Win3.x apps) or both, but this problem would only last a few years at most. Eventually 286s and <4MB of RAM would become obsolete. (And BTW OS/2 2.x not running well in 4MB of RAM had more to do with the Workplace Shell, MS had similar difficulties with the Explorer shell too)
