+1, thats a great idea
I want to emphasise the fact that the "re-synced" pokemon becomes untradable. Without this the idea would be a bit "too" good as you could choose to resync good pokemons just to sell them after for a high price.
Talking of the idea itself, its a huge QoL in my opinion, every PvE hunter experienced at least once an awful fail-sync during their playtime. I don't wanna be rude, but i'm not a fan of people talking and downvoting the thread without any real critisism. (I bet most of them never tried to hunt anyway :^))
Sometimes you have to invest more than one full week of intense farming just to get a nice T1-T4. In the end, the result is often a sync-fail. Now imagine this while farming a T8. Do you think a player that only get pokes by doing trades (in other words, a reseller) can understand this? I could even say that they wanna downvote this thread because they fear the fact of not being able to buy ALL the godly pokes anymore. (to resell them after lol, the irony)
The game is already really hard and grindy, I dont see how this feature can "destroy" the game or even impact the economy. (which is already a bit screwed anyway)