I would be interested to believe why you think this. There are no reports that Nixxes have in any way expanded and over the past ten years have managed - on average - one significant platform port a year. Why would they be better now Sony own them? There is no information to suggest have more people so how would they be more capable at producing ports?
Only time will tell. I also don't think Nixxes will be on the same PC port cadence as they were prior to the acquisition since Sony may open the floodgates, allowing them to multitask many titles at the same time.
Nixxes wasnt that large of a company before (as far i remember), mostly doing some low profile pc ports. I doubt Sony would aquire them for one port a year or so, instead i believe Nixxes is there to help and aid in the porting process for Sony's studios, as was said by Sony themselfs.
I mean, if Sony says we should expect more PS games coming to pc, and were actually seeing quite many of that in just the last two years, its probable we will see more of it. How much more and at what pace is anyone's guess for now though.
I think its just great news that the PC platform is recieving Sony games from now on aswell, this is a market Sony never would have reached with those games as pc gamers are a different market than console gamers. Those two markets will co-exist for a long time to come.