There are a couple problems here, the first is that the PS4 sold over 50 million near the launch of the first PSVR, and with supply issues combined with better competition, the PS5 being $200 more expensive, and higher game prices, I am not sure it's going to reach that by late next year. If the PSVR 2 releases earlier than that there is no way that's going to be possible.
You are also looking at PS5 sales in isolation, if someone prefers the competition, or buys both, that would be an incentive away from making an additional investment in PSVR. Someone may see that the Switch is $100 less than PSVR and may decide to get one of those to compliment the PS5 instead, there are a lot more variables involved that weren't there with the PS4. This is of course assuming that the pSVR2 will match the first and cost only $400.
The Xbox Series being more competitive than Xbox one is relevant to PSVR2 sales since they require a PS5, the price of the PSVR2 $400 or possibly more, is also relevant, what other gaming devices you can buy for the same price as PSVR is relevant, the $200 price premium owning a PS5 over a PS4 slim in 2016 is also relevant, $70 games are relevant, the game delays are relevant, the combined prices are relevant, the lower cost of entry for PC or standalone VR is relevant, none of this did the PS4+PSVR1 had to deal with.