As far as WZ2100 FOSS developers are concerned, it probably makes sense to drop OpenGL 1.x as the vast majority of these systems were 32-bit, and 32-bit Linux is reaching the end of the road with very few distros actually officially supporting it any more. (Though bad luck if you have a Core 2 Duo with G35 graphics).

As far as MorphOS is concerned, there's absolutely no point to try porting recent (> 2015) versions of WZ2100. Almost nothing has been added to the game itself.