He likely has a hidden agenda, why would you backstab Bitcoin like this? Bitcoin needs to proof it is anti-fragile (and it does!) and that it can deal with any kind of attack, political as well.
It doesn't.
Fungibility attacks through regulation are pretty easy. Let me give you some examples:
*Forcing mining farms and mining pools to filter certain transactions. If you don't comply,you are in violation of AML laws.
*Force exchanges and payment processors to hand over their customer data. integrate that with blockchain analysis, crate a blacklist
*Enforce this blacklist through regulated payment processors and exchanges. Incoming blacklisted money need to be send immediately to the government wallet (civil asset forfeiture). You may have the chance to claim some of it back if you can prove that you received the BTC in a legitimate way.
*Automatically blacklist coins if you do a multi-input/multi-output transaction. only transactions allowed are "1 in, 2 out" (a spending transaction) and "multiple in, 1 out" (a grouping transaction). Businesses can get a license to be allowed to do other kinds of as well.
*If you have blacklisted coins, no worries. You can get them whitelisted if you pass them through some "government whitelisting agency" where you need to provide ID, proof of residence and of course a proof you got the funds in a legitimate way. (and maybe pay a fee for this service)
*If you want to avoid all this blacklisting/whitelisting hassle, just use a wallet provided by your favorite payment processor that already contains your identity information and your address. it's very convenient and you don't need to bother with the different kind of allowed transactions. your wallet just complies automatically
When government can regulate something, they eventually will.