I don't believe this for a minute. Look at the list and numbers of these items given to the Taliban when Biden abandoned Afghanistan. We haven't even replaced them for our own readiness. We do not have unlimited supplies. What UKR has gotten in terms of advanced weaponry they haven't been able to repair or maintain (like the M777s) - just shoot and use til they're sidelined. The more advanced a system is the more extensive its support and maintenance requirements.
It's unrealistic, IMO. And, recent reports that UKR wants weapons like the very expensive THAAD (a very long range ballistic weapon) and F-18s, C-117s/130s etc. are equally in short supply.
The stuff left in Afghanistan were never coming back anyways, mraps, humvees… are in great supply and are actually being replaced with newer models.
Your point on higher tech systems is accurate, but the supply source is far greater in the west than in Russia. As for M-777 specifically I think the supply and reconstituting capabilities are there, M-777 was designed for war with soviets, not really a player in a Chinese conflict so supplies are there, is the will to supply and produce them, always a question
There are plenty of posts on stocks in storage so I won’t post them again, but they are in the thousands.
Western production as well as Ukrainian production are ramping up , Russia is too, but they are not the Soviet Union anymore and production is in the 100s not 10s of thousands.
We will see