A few things to keep in mind:
1. The other races HAVE been reappearing for registration here and there but you have to be super quick to get them. So you could sign up for the ten miler then gamble on signing up for another race or two separately. You can follow this twitter account to track openings, I’ve never tried to sign up via this account so I can’t vouch for how easy it is to sign up through this method but it is an option.
https://twitter.com/rundisregstatus?lang=en
2. BUT! You raise an interesting conundrum. Signing up for WDW MW 2024 is a nice option. You get the half marathon that takes you through Magic Kingdom and a race weekend that is otherwise pretty neat for runners. And obviously if you want to run a marathon that’s the weekend to go.
3. The ten miler is expected to be a completely different map from the WDW half, likely taking you through HS instead of MK (entirely possible it doesn’t but since it’s Toy Story themed it’s a good bet that the race will go through Toy Story Land and the rest of HS).
Ultimately it’s your call depending on your preferences but both weekends should be fun.