The government of El Salvador can do whatever they want with their BTC, but a few things come to my mind.
1.There's no "quantum threat" coming anytime soon. Why are they preparing for this so early? Maybe the "quantum threat" is just an excuse and there's another reason for the government to move the BTC to multiple wallets. What if the IMF wants to take control over El Salvador's Bitcoins?
2.Why 14 wallets? Why not 50 wallets or 100 wallets?
3. A quantum super computer could be theoretically capable of brute forcing all seed phrases. I don't believe that moving the BTC to multiple wallets could diversify the risk. Maybe they should add seed phrases with more than 12 words. I'm not an expert, so maybe we should ask some actual BTC developers about this.