There was a change, but it was a few years ago. The arb salary demand used to be based on a combination of talent, playing time and performance. However, for a while now it has been based on just the overall rating of the player.
If you're asking if the logic has changed for how the sim determines who wins the hearing, the answer is no (as far as we know). I have noticed lately that I am nearly 100 percent lose on position player arb hearings so I can see why some folks think something has changed, but I think it is just luck. I have won more arb hearings than I have lost on pitchers lately. Not sure if this is normal. I only seem to notice it when I have a lot of arb hearings in one season though. As mentioned above, the trend for me is lose on position player, win on pitcher.
My arb strategy is a combination of a rule for arb1 and a play it as it comes for arb2. I nearly always sign my arb3 guys long term to avoid arb3.
For arb1 I always offer 396,000.
For arb2, if I play the player a lot and he performs where I expect, I offer something closer to his arb demand (85+%). If he hasn't played a lot or hasn't performed to where I expect, I offer something further away from his demands.
As stated above, my results are a mixed bag.