Whilst I do not believe in the fiat system in general terms, this makes no sense.
It is true that COVID is suppressing consumption and therefore inflation in a lot of countries, which means that inflation figures haven't actually jumped that much even though there have been several rounds of economic stimulus by fiscal and monetary means in most countries (stimulus checks, QE, etc.)
But how is it "protecting" the fiat system? It just isn't. Sure, inflation hasn't jumped during COVID due to low consumer sentiment, but have you considered the fact that QE and other stimuli wouldn't have even been warranted without COVID?
The real concern with COVID on the economy should be that it is propping up asset prices such as equities because excess liquidity has gone towards speculation more than anything else. Not that it is somehow "safeguarding" the value of fiat.
Interestingly inflation levels increased a ton in some nations for the exact same reason and that is why this is all wrong. You know how it increased? Since people couldn't work, and since people couldn't make money, instead of selling 10 things for 1 fiat and make 10 fiat, they started to ask for 10 fiat for 1 thing to make 10 fiat.
This is just an example and numbers are made up but since people couldn't spend too much money on bigger things, the only thing money went to was needed things and that made everyone poorer and asking for more and more money, which is the reason why there was inflation. That is how happened in my nation and that is what happened even in USA as well for a while, during summer specially everything was a lot more expensive. You do not think that going to cinema in the future when all of this is over will be same price? It is going to be a lot more expensive, those places didn't even made a cent during this period.