Bitmain's contingency plan against UASF was UAHF. According to the below statement UAHF would be deployed if Segwit2x fails to activate Segwit or BIP 148 has the majority, right now it is Segwit2x all the way.
If BIP148 activates then UAHF will be alive on the same day. The UAHF chain will protect the economic transactions that are under risk of reorganization because of UASF. Later, we will support the activation of SegWit on the UAHF chain if there is no patent risk associated with SegWit and if the arbitrary discount rate of witness data segment is removed.
The ABC specification falls in line with mining hardware manufacturer Bitmains hard fork protection plan against a User Activated Soft Fork (UASF), but Bitmain has not officially endorsed the ABC project.
Bitcoin ABC is a full node implementation of the Bitcoin
protocol. We have removed the controversial SegWit code,
replacing it with a simple, sensible, adjustable blocksize cap.
ViaBTC's UAHF plan doesn't have Segwit.
If I am right there would be a UAHF only if Segwit2x fails.
Bitmain UAHF, ViaBTC UAHF, let more pools come up with their own UAHF and create Bitcoin ABC, EFG, or XYZ. Still there be only one Bitcoin and rest alts.