The huge loan for their new stadium, coupled with the covid losses (loss of attendance receipts, advertising revenue and TV money) devastating their planned repayment schedule while extending interest payments into the future, means that Spurs have taken a financial kicking.
If they’re laying money out under the above conditions then it seems pretty obvious that they’re assured that money is coming in and you don’t need bad math to see it.
I would suppose that there’s a fair likelihood that City and Spurs are in agreement over the Kane deal and the announcement is put back to allow Spurs to make purchase without being seen to have pockets full of money and a desperate need to recruit - much as we saw happen with the Grealish purchase.