Do not hold your tokens for too long without looking back, I have lost some this way because later they move to main chain running on separate blockchain, imagine if you decide to check the progress of that project only in 2024 and you see that you've missed out on swapping your old tokens to the new coin..
Maybe you are pertaining on blockchain tokens that already migrate from testnet/initial blockchain to there mainnet but if you are holding blockchain tokens running on mainnet, You can still recover the new coin once the team decided to do a hard fork.
Can specify what is the exact token/coin you bought that you missed the swap. AFAIK, You can always contact the team to manually swap your token even though the swap period is over since they will mint the same amount of supply of the old token to the new blockchain so basically your unswapped token is just seating on team reserve.