This seems unlikely. Luka is too good of a story, and no chance Westbrook overtakes his own teammate who is leading the league in scoring
Harden in 2020: 30-7-7 with 40 percent shooting, 32 percent from deep on 12 attempts per game. Westbrook has significantly outplayed him in 2020, and if that trend holds, I think you can reasonably argue that Westbrook was better than Harden, who has been pretty bad in 2020 despite still scoring at a good rate.
Luka is a great story, but has he been better than Westbrook this season? 28-9-9 on 46 percent from the field and 31 percent from deep on 9 attempts per game is good, but not as efficient as 2020 Westbrook. Westbrook is also a better defender and if Houston wins a lot more games than Dallas and finishes as the #2 seed, I think Westbrook has a case, even though his 2019 was so bad. I'm not saying that it is likely, only that it is possible.