Many Cubase/Nuendo users rely on a mixing environment with lots of plugins which are not available as VST2 and in other cases VST2 versions from specific vendors actually work reliably while VST3 do not.
While VST3 is preferable, it is not always possible to switch. To discontinue VST2 now would be a tad too bold.
You should really ask the instruments’ devs to update to VST3 the instruments you need and give you a choice, rather than ask Steinberg to take it away from anyone else.
Locking this before it further degenerates.