This is an accepted solution.
Thanks for connecting with us. My name is Olivia and I work at Shopify.
Great question around onboarding to the new Facebook Sales Channel. I can confirm that once you have onboarded to our new channel, you can remove the old Facebook Shop and Instagram Sales Channels. They serve no purpose at that point, and have already been delisted from our sales channel options.
I hope this answers your question, but let me know if I missed anything.
So glad I could help, @lightmove.
Don't hesitate to reach back out if any other questions come up.