I don't know, I do not think that firing Pochettino was a big mistake, I feel like he did not do all that well with the team he was given. I get that they are getting young players for overpriced offers so that they could build a team that would play together for a long time, and that could actually be a great idea on the long run, and they are avoiding the financial fair play hit by just giving them very long contracts as well.
However, unless they make something now, like at least be in UCL or something, then they are not going to get anything at all, being a loser for a few years doesn't make you great, you need to have good results, to aim for great results, you do not get bad results to aim for greater results.
I don’t think so too, i would even say it was the best thing to do because there was no impact on the team until towards the end of the season and he doesn’t seem to suit what the owners want to build. They want to build a team similar to Arteta’s and what Pochettino was building is far different from that. There is no guarantee that pochettino will do well next season and make top 4 but at least the new coach is an ambitious coach known for having good relationship with young players and the players Chelsea are busy buying are all young players with prospect.
Both the board and the players long for European football, it’s good that they didn’t miss out totally and will participate in the conference league at least but all hopes will be on the new manager to lead the team and secure a champions league spot next season. I believe they will have good results next season.