Is there really no launcher entry at all for freshly installed Android apps or is just the icon not displayed, but the App title is there and the space for a launcher entry is occupied?
The latter happend often in the past, but only rarely or never lately, on a Jolla 1, but after some time (and many reboots) Android app icons were always displayed in the launcher.
Currently I also have two Android apps (out of about 20 new ones installed after upgrading to SailfishOS 3.0.2) not displaying their icons on an Xperia X. This is already persistent over a couple of days and reboots. But the launcher entries are there, with app title and space occupied, thus these apps can be launched by tapping on their invisible icon (in contrast to your issue description).

And are really all Android apps affected by this is issue on an XA2, which have been installed after upgrading to SailfishOS 3.0.2?