Yes, it seems that the match that will definitely be much more difficult for Arsenal to face is against Newcastle, because Newcastle definitely needs a win to stay in their current position. So in my opinion, Arsenal would be better off winning against Liverpool, because it seems that Liverpool are not too serious anymore, because they have secured the English league trophy. So winning or losing will not be Liverpool's goal at this time. That is why Arsenal must take advantage of this to secure their current position and to secure a ticket to the Champions League.
Because if Arsenal loses to Liverpool and then doesn't get good results when facing Newcastle, there is a possibility that Arsenal's position will drop. Because currently the achievements of the teams in 2nd to 5th place are not too far apart. So just one mistake can be fatal at this time. That is why Arsenal really has to put in their best efforts, so that they can be even safer. And for the Arsenal vs Liverpool match, I personally will bet on Arsenal in this match, because as I have explained, Liverpool currently seems to be just playing around with the remaining matches.
Yes, I agree with you, that when Liverpool faced Arsenal later, Liverpool was actually confirmed from the start as the champion and they faced the match casually, because for them the match would be played in front of their supporters, and I saw Arsenal were quite disappointed after failing to advance to the next final in the Champions League, even so, both teams will show their performance when the match arrives.