Mateta seems a likeable character, and I suspect he played a key role in the positive group dynamics of the cup-winning team. At his best he holds the ball up well, brings others into the game and, of course, gets a decent number of goals.
When I say a decent number, its worth remembering that he got 16 league goals in 23/24, 14 goals last season, and has 8 so far this season. For context, the only people to get those kind of numbers since we got promoted are Zaha with 14 (21/22) and Benteke with 15 (16/17). Otherwise, you have to go all the way back to Andy Johnson (21 goals 04/05) and then back to the early 90s with Wright, Bright, and Armstrong to find a Palace forward with 15 or more top flight league goals. Accepting of course that we haven't always been in the top flight, that still shows how hard a regular goalscorer is to come by.
At the same time, I find it hard to get past the old saying that form is temporary, class is permanent. For me, Olise, Eze, and Guehi were all class, but Mateta has just been in great form. He has done really well when supported by the best creative attacking talents Palace could ever hope to have, and far less well otherwise, including a couple of years of really stinking the place out before coming good. He is turning 29 at the end of this season. Even if he had three or four years left on his contract there would be a decent case for selling him now, at his peak value.
In telling the club he won't be signing a new deal he has done the decent thing by Palace, who can now make plans. The question is what should those plans be? I cannot believe Palace would sell to Forest under any circumstances, but certainly not when they are near us in the table. I would rather take a bit less money from someone else.
The timing of the sale doesn't matter hugely (now or summer) IF reinforcements are secured in advance. This is not like Geuhi, where we had to sell now even without someone lined up. If we sell Mateta now and do not spend the money in a way that obviously improves the team, that could not only make the team weaker, but also undermine morale.
Right now, I don't think a direct replacement for Mateta is necessarily what we need. I don't see the attraction of the boy at Wolves, for instance. We are struggling to create anything. We need a clever, jinky dribbler with an eye for an assist, or more creativity in centre midfield. Even if we get a good striker in, as things stand they will find chances hard to come by.
Plus, either now or in the summer we need to reshuffle the pack a bit. We have spent a lot on Nketiah and Johnson, not to mention Pino, and cannot write them off. I would be happy for Nketiah to have a run at No9. Johnson plainly cannot play as a No10. He might do a better job up front, or wide right in a different system. Both players have decent pedigree. I doubt the next manager will play the same system as Glasner now that so many of the key parts have moved on. Without taking anything for granted this season, the Mateta sale/spending money issue must be assessed with at least one eye on the future, and that future must include getting value out of the existing investments.