BBM public server was certainly blocked as early as 5 years ago.

Blackphone servers at around 4 or 3 years ago as well, just few months after its market release (while signal is still available though)

All modded GSM phones were under blanket ban for even longer. Modded GSM phone vendors are routinely raided.

Then Line, KaoKao and gazillion of others.

There is no doubt that they were very deliberate in targeting anything with hard crypto.

FB, and Google are routinely complying with Russians, so no wonder about them still being there.

> modded GSM phones

What do you mean by this? I'm genuinely curious. "modded GSM phones" yields zero hits on Google for me.

Stuff like TopSec S35 or Security AG. Some are garage made. All of them basically put a block cypher in between the GSM codec chip and the modem. Such stuff was relatively easy to do on old dumbphones

Are there any modern incarnations?

Thanks! It's even more suspicious why Google and Facebook products still works then... And they have never been blocked.