goon If they have a good idea what other interest is like, it'll be because they've informally invited other bids. If they're using other interest to haggle over clauses, same deal.
I reckon the real motivation to sew up this kind of deal early is mainly to de-risk the next one you're lining up. But that doesn't stop United coming in £20m ahead of us as Chelsea did with Mudryk. The Premier League hasn't ever had so much of that Madrid, Juve, Bayern syndrome you mention.
Overall it's hard to credit this being all the way done at this stage.