The simple answer is yes. They'll remain valid as long as the expiry date set at link creation is still valid.
Do tiny links expire?May 6, 2020 by Sean Thomas
Services like Tinyurl say in the first paragraph on their main page that their urls "never expire": tinyurl. ... This Bitly help page also states that their urls won't expire while services like 1TinyLink, offer temporary urls from 1 to 30 days long, destructive urls that expire once open and permanent links that never expire.