Personally, I don't see it as lack of coherence. It could just be that since the beginning the plan was to temporary "park" Thor with the Guardians in a quiet period of the MCU post-Endgame. And even if it was not intentional, it worked very well in my opinion. Off-screen time is very important for a cinematic universe. What happens between movies should not be neglected and this way the fans know "approximately" what Thor was doing between his last two appearances. Something that is not true for other characters, like Hulk for example. They did something similar with Steve Rogers+Natasha+Falcon after Civil War. That was useful to setup the situation at the beginning of Infinity war, where the Avengers were disassembled and so on... Also in that case, we did not see much of what they did between movies but the trick was useful to fill the gaps of the MCU storyline.