Don't buy it, they are trying to hold that info the longest possible to try and have MS reveal before, and there is still time before launch.
The only way that is possible is if they are going boldly low and are sure MS won't counter
SNY seems to be playing fairly nice so far, so I really doubt this, but unless they were to try and bait MS like AMD did to Nvidia somewhat recently, I can't see them going first, especially if Lockhart is coming and is close to the rumored specs.
SNY could go first and say PS5 is going to be like $599 and $549(DE), hoping MS doesn't want to go any lower than they have to, making XBSX maybe $549 or $599. Then immediately after MS decides to announce the XBSX price, like the very next day at the latest, even though XB fans may be rejoicing that their top tier console will be cheaper, SNY pulls a "jebaited" and says the prices were always going to be $499 PS5 and $449(DE) at launch.
PS fans probably wouldn't be very negative at all if they did this, in this specific way, yet it would look really bad on MS's part if they followed suit and dropped the price as well afterwards, because it would look like they were the one's being greedy. Now XB fans would likely say SNY was lying and was hoping to screw their customers and was forced to drop price because XBSX was lower or at par. How XB fans would take it overall is hard to say, but they obviously wouldn't be as happy as they were before, while PS fans would be surprised and may get a good laugh out of it.
This would be another huge kick in the nuts moment like 'this is how you share games' if it were to happen. I really doubt it though.