The regular ps5 and xsx will be the same price. The xsx is more expensive but they will match Sony at whatever they anounce. There's no need for them to eat a massive loss as the already have the power narrative so being the same price is a plus.
Which means Sony should just anounce already and set the new standard for price. Such could be $450.
MS fully intends to match the price of the PS5. That's what is causing this waiting game. But there is that possibility that sony could just announce the PS5 at $449 as you said. That would force MS to also price their console at $449. But they probably don't want to do that, so they will wait as long as they can and see if sony just prices the PS5 at $499 instead.
I feel sony delaying their price announcement is indicative of them willing to be at $399 for the PS5DE and $449 for the standard PS5. And that pricing has more of an effect if they wait for MS to first announce $499 for the XSX. MS obviously doesn't want that, but also won't commit to a $449 price point unless they absolutely have to.
And so we wait ad watch them keep playing this game of corporate chicken.