Banks use tools as a store of value by holding some assets in reserves, for various economic benefits. Although, adopting Bitcoin in such capacity, would have it's pros and cons. Obviously like controlling inflationary trends, and even help stabilize the volatility of Bitcoin to its users, and conversely such volatility could also alter the stability of a banks statement of financial position. All these could add up to a more stable global economy. Surely banks have started to think of such prospect
1.I don't know anything about banks storing Bitcoin as part of their reserves. Can you share with us any verified information about one or several banks storing BTC as a reserve? If the answer is no, you are clearly speculating about this subject. AFAIK, most commercial banks around the world aren't allowed by the central banks and government regulations to store BTC in their reserves.
2.Bitcoin's price volatility cannot be lowered by banks storing BTC as a reserve. Bitcoin's price would always be volatile, due to the unstable supply.
3.What do you mean by "controlling inflationary trends"? Bitcoin cannot protect our wealth against inflation in the short term. The best example would be 2022, when there was high global inflation, but the BTC price dropped from 50K USD down to 17K USD.