How long will updates be made to Monterey OS

It is unclear if Apple will release any further point updates to Monterey now, or not, but it will continue to receive Security and browser updates while it is supported until sometime in the Fall of 2024.

Apple has been supporting the 3 most current versions of macOS. Assuming nothing changes, another 2 years.

Just to be clear, Viking is correct in that there's no way to know if there will be any feature changes to Monterey in that time.