I'll take your bet on this. Silicon designers aren't unaware of this potential vulnerability, and if you want to prevent eFuses from being un-blown, you can design for that. I would place money on there not being any commercially viable way to restore an eFuse in a 4090 die at any point in the future. You can probably do it, but it would require millions of dollars in FIB and SEM equipment and likely would destroy the chip for any useful purpose.

Usually the only useful reason to attempt to recover/read/unblown fuses is to read out private keys built into chips.