Who ever mines BU will lose all the money they spent on mining it. So that 50% threshold means nothing. Any fork of Bitcoin will be attacked ruthlessly by those who have enough resources to destroy any miners foolish enough to try.
The large miners/pools know this. The April's fool joke is on anyone who believes that signaling means anything on Bitcoin. It doesn't.
add to all that bugged coin will be used and will be on exchanges then magic will start
from dev side attack, miners can lost not only time but even more a mined BTU with some major fail can go to 0 in NO TIME... BU is for blocking segwit.
Without segwit Bitcoin will slowly loosing dev warfare over alts like ETH and many people will move to ETH till its implode...
If ETH won't implode it will move away from BTC then miners will be realy fucked
once you lose market and users tasted fast cheap currency expect problems.
BTC won't go on track without any improvments on way.
Increasing/unlocking blocksize its making BTC like alt coin tweek number and go...