Personally, I've never had to replace anything. Most people don't have to replace anything. Unless you plan on shooting thousands of rounds, which costs a lot of money and time for range trips etc - yes we'd all love to - but if you're new, be realistic - you likely won't have to replace anything.
If you can afford it, sure, doesn't hurt to have extra springs, striker, maybe a drop=in trigger kit etc. Definitely buy at least 4 extra mags and base plates if you're the kind of guy that drops your mags.
But I've known guys with Glock 19s that have never even cleaned theirs after 20K+ rounds, let alone stripped or replaced parts.
IF and a big IF this "freeze" happens. I still find it interesting that they aren't calling it a ban. The CFO lady I talked to today thought it was weird that it was so busy, and she's right in the thick of it all. But doesn't hurt to have extra parts on hand if you can afford it, even if you never need them. I wouldn't hoard multiple of the same thing though - unless you're buying a cheap garbage gun to begin with or a quality one with a single known issue or part that has multiple complaints about a specific part.
Basically don't hoard toilet paper. There's always more.