Bitcoin Core mandatory update means segwit is no longer optional. All core nodes will now have segwit. You could still run other implementations but few do that.
That is a good point, but I had the impression that full nodes was not used much for transactions in general compared to light wallets. (I may be wrong there).
Ah but the bitcoin maximalist mantra is everyone should be running a full node and there are no real spv wallets.
