Hopefully, the preventative change to remove the closed-source ASIC Boost advantage (currently in a work in progress) will reduce Bitmain's hashrate enough to push Segwit above a 51% signalling rate. No miner likes the orphaning risk that 51% signalling of any BIP represents, so BIP 9 (Segwit) might get enough of a boost from the Anti-ASIC Boost BIP that Bitmain will lose 20-30% of their hashrate, and Segwit signallers will fill the gap.

With Segwit at over 30% now, I would expect alot of the miners and pools who represent the holdouts to finally get on board (node support is now over 60%). And maybe even former BU miners/pools will switch, now that BU is officially dead in the water. That makes the prospects for 51% Segwit acceptance pretty good today, so even UASF might be unneeded, the miners might yet activate Segwit.