or will it be Sys? if merged mining is desired for VIA then I think the larger issue will be to introduce to a pool that supports the upgraded stratum. Rebasing to btc 0.13.1 is the easy part.
Introducing to pools might be easier. I'm pretty sure.. Almost know for a fact that they are ok with Segwit for Viacoin. I heard good things about 2fa pool owner and him being and I quote "a chill guy". However I would chill too with a couple mil
Merge mining is actually quite easy implementation. The version bits is the trickiest part about that but no more than a few hours. That is good... i mean there are only a handful of pools for bitcoin so being on them would be a good thing for security of your network.
via uses scrypt algo (just like ltc)
so pool ops can test their segwits in order
1. upgrade and test via pool, if it works
2. upgrade and test ltc pool, if it works
3. upgrade btc pool :p
just like for example bip65 (CheckLockTimeVerify) was first tested on via, then went live on btc