Sure it will fit. If your asking if Pivot will offer as an option -highly unlikely given Pivots relationship with Fox.
As I have recently found out Pivot does not endorse the use of anything other than Fox suspension products when I asked them about using brand x coil shock. In fact I was told doing so will void your warranty, at least when it comes to rear shocks, not a big deal imo but kind of frustrating but understandable given the need for a very sepcific DW tune.
I tried it on mine. I have a medium/medium tune for my Nomad and it works extremely well on that bike. On the Firebird, not so much. It had way too much compression damping and I could only access about 2/3rds of the travel, even when I bumped the sag to almost 40%. Plus you have to shave the aluminum rocker a little bit for fit. By a little bit, I mean just a tiny bit like if you chamfered (or "broke") a sharp edge. It would probably ride real well if you got one with a medium rebound and light compression tune.