I think the foundation behind TON is quite conscious about the scalability issues, I guess they will propose solution like what solana did in their testnet but I don't think it will be solved anytime soon.

the problem was quite similar to solana too, but it also goes to show that TPS that are tested in lab with perfect set up doesn't guarantee same outcome in real practices. so, many blockchain that claims to have hundred thousand TPS is just marketing buzzword unless proven otherwise in my opinion.