I've never heard of anybody waiting a year to starve out fish parasites. Is there reason to suspect they're in the tank? And, if so, why not treat for them now?
If your plants came from online sellers, and some forum sellers, they might have been emersed-grown, in which case they'll generally melt before they put out new growth (they switch from emersed form to aquatic form). You can trim or leave old leaves. If you leave them, they'll just become food for new plants.
If by the time you add fish, the tank is heavily planted, you'll have no worries about an ammonia spike, as plants will consume excess ammonia. Some members swear by a fishless cycle in which they plant heavily (heavily enough that it's difficult to see the bottom of the tank from directly overhead), fill the tank, and drop in fish immediately, with no losses. Not sure I'd feel comfortable trying that with shrimp, but some likely would.
If you're concerned, you could add a few pinches of fish food daily until you toss in the shrimp. The decaying fish food will take the place of adding ammonia. It's probably not necessary, but it would keep ammonia introduction leveled out.