I've finished it once, I guess if you feel invested in all that lore and history they keep talking about then it would be a really great experience. For me, I couldn't be less interested in which god once farted in which other god's face or whatever so I barely ever paid attention to any of that and pretty much powered through the main story. Still a pretty good experience in terms of visuals, cinematics and combat no doubt.
As for the rest, are we sure Odin and Thor are gonna show up as enemies in the next one. For one, there are some theories that the dream Atreus had about Thor coming to their house is actually not a fight but Thor coming to Kratos for help regarding Ragnorak. But even otherwise, if they show up as enemies, based on the main story enemies we had in this one i.e. Baldur, Thor's sons and the rest of random stuff, they were all pretty manageable, especially as compared to the Valks where the boss design is quite challenging and you have to be on top of your reflexes. But the rest of the main story enemies were always too slow and gave massive windows between attacks, unlike the Valks. Based on that even if Odin/Thor etc show up in a fight they'd probably be on the same lines, as I feel they don't want to make the main story too hard for the mass audience. For those interested in harder fights, they've added the Valks as optional in this one, and could have something like that.