Ultimately all sets of packages are a consensus - either a company says "we only use these versions of these languages and libraries" or it's a whole community. (This honestly beats the laissez faire approach which always blows up somewhere)

It's something companies shoukd consider doing internally as well - this API is supported at this version etc. It's easier to do explicitly than implicitly (large companies usually have internal SLAs and actual written docs)

I think the point I am making is good deprecation is part of good contracts.