I think that Remco fans should be pretty happy with how he's going. The man has had his main season objective destroyed by covid, and yet in 2023 he has still won LBL, the UAE Tour, placed 2nd in Catalunya and 3rd in Tour de Suisse. That's a very good season for most riders, and it's only half over!
Regarding the Vuelta vs. Lombardia debate, another Vuelta has to be rated higher than the 5th monument (it's not as much of a target for riders as the other 4 monuments imo), but to me Remco is much better suited to winning Lombardia. His strong suit (along with ITT's) is simply hilly one day races in excess of 250 kms, where when everyone else appears on their limit, he still has an extra gear to go to. He just isn't as suited to GT's where the stages are only 150 kms and skeletons hide for 95% of the time until we get brief showdowns on HC/cat 1 climbs.
As for 2024 he should ride the Tour, but without it being a be all and end all goal. A top 5 GC result would be decent, but I wouldn't go for a Vingegaard super peak if it meant jeopardising other goals (LBL obviously, and maybe try Ronde).