If that's the case, maybe the tweet has real truth to it. The club are happy to go with Zinchenko and Cancelo another year till Brighton reconsider, and as such Zinchenko would also rather stay.
What is often missed is that there's a difference between wanting / needing to sell & realising that what the buying club is offering is already a really good deal and trying to maximise that (which you couldn't criticise Brighton for doing). That is where I think Brighton are.
I think that City & Zinchenko are at the point where we'd prefer Cucurella than Zinchenko (why we've agreed a deal with Arsenal), but in all truth Zinchenko would rather stay and will only go if Brighton accept an offer for Cucurella. I think that this is part of a tacit agreement between Zinchenko & City.
The only way that this changes is if Brighton refuse to sell, we reach a deal with Brighton, or Arsenal start to put a lot of pressure on us to sell now (which I'm guessing would be good for Brighton, as our preferred choice is obviously Cucurella, and might force us into agreeing a higher fee).
As yet none of these things have happened, but as I say, I think the Blackburn tweet is essentially our 'je t'aime, moi non plus' to Brighton, letting them know that we can cope if their demands are excessive.
45m is a lot of money to a club like Brighton as it was to us before the Sheikh (MAHTBCT) tipped up.
One thing's for sure, and this is our strength in negotiations, we're winning the PL again next season.
One thing that's also sure, and this Brighton's strength in negotiations, is that we probably won't win the CL unless we get a LB capable of swapping for / covering for Cancelo (if he goes to RB or gets injured / suspended).