The comment is a bit poorly thought out.
It would be picking a fight with Putin on his terms, him being former KGB. He has a tendency to order poisonings - ask Kyrylo Budanov, he narrowly escaped eating heavy metals and his wife Marianna was poisoned. Doctors saved her, but she will likely need long-term treatment.
Russia also still has satellites in the sky, moles in US agencies and spies on US soil - so Putin would have a decent chance of knowing. Trump and Vance would not want to personally die in gruesome ways or lose family members.
Russia also has a tendency to detain foreign citizens (including but not limited to spies - businessmen also have a high risk) on various excuses, eventually exchanging them for Russian citizens detained abroad if they're in favour. They know the game of kidnapping and exchanging people. They just do the kidnapping on their own soil.
If "what to do next" would be stopping to f**k with military assistance to Ukraine - to sell the tools they need, even if Biden gave tools for free - yes, I would agree, that would be logical. But Trump has demonstratively sabotaged assistance to Ukraine from day one. It's a bit far fetched to imagine he would reform himself.
I don't know if the Kremlin has leverage on Trump or Trump has delusions about the Kremlin. If they have a special relationship, it would be nice if it broke down over Venezuela, but I don't see it happening - I see Trump threatening Greenland, Colombia, Mexico and Cuba.
Correction of facts: the announcement is still up or has reappeared, though it was inaccessible for a while, enough for some journalists to provide an archived copy.
Personal opinion: