some random 4400 theories after my latest rewatch
The future doesn't have tech that lets them predict what abilities people develop; they knew because all of the 4400 took promicin in the original timeline. That's why the disappearances only go back to 1946--they had to be people who were alive when promicin became available.
The reason the future originally didn't want Shawn even though his ability is so world-changing is because they wanted him to be one of the first people to take promicin and forever associate taking promicin with amazing healing powers.
Kyle's visions-of-what-needs-to-happen ability was a lynchpin of the future's plan and his coma required a lot of adjustment. (Including deciding to give Shawn his powers early so that there was someone to wake him up from the coma.)
