Not with quantum computers. I assume we won't need to wait 1500 years for the next generation computer to be developed.
Quantum computers are not a magical bullet that can instantly solve any problem. They provide an exponential speed up to attempts to solve the ECDLP, and this is the main way they would be used to attack bitcoin. They provide a much smaller speed up to any hash functions, which is the limiting step in attempting to unscramble a seed phrase, since you must use a SHA256 to calculate the checksum, followed by 2048 rounds of SHA512 to generate the seed number, followed by several more rounds of SHA512 to work down the derivation path and generate the necessary addresses to check for funds. They will be able to speed the process up, sure, but they are unlikely to make unscrambling 18 words any less unfeasible for the average person.
Its just a simple matter of adding more words.
The security of your wallet should never depend on there being enough words in your seed phrase so that an adversary with access to all the words cannot unscramble them, but rather on an adversary never having access to your seed phrase in the first place. I would
never scramble the words in a seed phrase to begin with, for the exact reasons highlighted above - if you mess up then wave goodbye to all your coins.