The club has stated publicly that the bigger issue was timelines being squeezed too much, and I do believe this. It would also make sense not to put more pressure on cashflow than is necessary right now.
I do think the transfer window will be interesting. I can see a lot of smaller clubs having to sell their best players in order to stay afloat so there's a good chance that some bargain deals could be done, with those clubs that do have money being able to hoover up talent from those smaller clubs (so Palace selling Zaha, for example, would be highly likely). Sadly, this will favour the clubs with artificial revenue streams from their ownership groups.
I suspect we'll fall somewhere in the middle - we won't need to sell but we may not have the buying power we would have had otherwise. I'm on the fence as to whether a transfer like Werner could happen. I don't think the future payments would be an issue, it's whether the club can find the cash for the first instalment to make it happen this summer.