This really is a non issue.
The rapid or blitz arena strategy for many players is to try and win each game quickly or even lose quickly, to accumulate points as quickly as possible.
Even though I would never have a look at even a top 20, I follow a similar strategy.... and in doing so, in many games against much higher rated players, earlier in the arena, I would support the process and resign quickly if down a piece say, rather than struggling on, trying to find good survival moves and taking lots of time from the arena clock, for both of us.
Consequently , some of the wins players get, are much quicker than they should be, with only a few resistance moves being played. So when the reverse happens at the end of the arena, lets call it winning on the swings and losing on the roundabouts.
No, it's not. It's using the format of the game to your advantage. In my opinion, there is nothing wrong with that. I fully expect my opponent to do the same - same thing with winning on time, premove tricks in fast games, etc.
However, I do believe that games that are in progress while the arena ends should be finished, whether it's for arena points or just rating points.