I don't think McLaren will continue to enjoy this sort of gap on other tracks, but I also think they will remain competitive just on the basis of how they have been performing since Miami. There hasn't really been any track type where McLaren hasn't at least been in contention for the win, if not outright the quickest.
I don't think a fair comparison with 2023 can be made. The 2023 car had inherent mechanical weaknesses which were quite severe. Those weaknesses were somehow balanced out by the car being "overpowered" on high-speed corners. The car this year is much more balanced, and although they have lost the high-speed lead, they're pretty much top of the class on most other corner types. Last year, the Monza low DF package was somewhat rushed and they didn't even have a proper low DF setup for Spa ready to better optimize a low DF setup. Not to mention the inherent drag problem the 2023 car had.
This year, with a relatively low DF configuration at Spa, they did rather well.
Remains to be seen how they will perform on an even lower DF configuration, but I doubt the deficit will be as big as it was last year. Besides, even last year, the car was half-decent considering the limitations. It's just that their straight line speed was so poor, they were stuck behind Albon the whole race.