This hypothetical situation though is a bit unlikely, as we're talking about quite a lot of money to pump into someone's campaign and anyone doing this will still be subject to attempting to manipulate the electoral process if they do not abide by the law, which could land them in jail and lead to an annulment of the electoral process.
There will be trials for this, and both the people who bought the ads (if they can be found), but more importantly the media publishers who pocketed the millions will have to answer questions to prove this was legal.
You can't unilaterally "pump some millions" to buy some electoral ads. Someone pocketed some millions and will need to show receipts.
If you also relatively think the couple that are actually in jail they are too few for the amount of politicians or general corruption that is in prevalent Romania.
Nothing will change from the annulled election to the new election (candidates will not be invalidated, TikTok will still be there). So if the annulled election was invalid on whatever criteria, the new election would also be invalid on the same criteria...
That would be the goal.