MK is replacing, not adding, in terms of pure attraction count since we are losing TSI and Riverboat and gaining the main Cars attraction and one other, so yes, subtract 2 and add 2. It is a wash in that sense. Now, will the new attractions draw more guests? Of course. But one or both will be behind a $35 paywall as mentioned, unless you want to stand in the sun for 2 hours waiting. Current management is obsessed with monetizing every inch of the park and realistically I see very few if any non LL attractions coming any time soon. Possibly the carousel at AK but even that is not a given since things like the Mad Tea Party have LL for no reason.
AK is also not "expanding" since we lost Primeval, Triceratops, Boneyard, the games, and Dinosaur, and gained Encanto, Indy, and a Carousel. Even if you believe them when they say the new land will have a playground it's still essentially a wash, and beyond the initial hype I don't see Indy attracting a ton more people than Dinosaur did as it is still the same ride so those who did not like it due to the motion or such will still not like it.
Won't even get into the horrid decisions made at Epcot, namely the central gardens that are a downgrade which is almost unanimously agreed on.
DHS at least finally reopened Mermaid and added the Villains show, as that park desperately needed and still needs some filler attractions.
Disney left areas like TSI and Dinoland to rot and then gets rid of them saying they are under utilized when they could have just improved them. Then they tell us we are getting "expansions" when in fact it's just repurposing existing space, even with the "blessing of size" meaning they really don't have to always remove something to add something, especially in a park like DAK with a paltry attraction count to begin with.
The destruction of the Rivers proves to me that current management sees most if not all quiet, non LL sale generating attractions as a waste of space. I fully anticipate in the future we will lose things like the Railroad, the Tiki Room, Carousel of Progress, even the Peoplemover (though its space couldn't really be used for anything else anyway). These attractions aren't IP and don't generate LL sales so they are guaranteed on the chopping block IMO at some point unless there is a drastic change in management.
Now, attendance in the summer is a hard metric to judge by as summer is the new "slow" season in WDW, replacing what used to be in Jan/Feb. I would imagine people are more willing to pull kids out of school for a week these days vs suffer in the oppressive heat of summer.