I get it from his point of view, other players will look at this and think they need to kick up a fuss and stinker like Isak or clubs will simply not sell them.
However from Palace point of view, Liverpool lowballed them all summer and only made an acceptable bid right at the end of the window leaving them little to no time to find a replacement. So they are quite right to not let the player go. Though sounds like the club wanted to sanction the sale but the manager kicked off.