Why this, specifically?<p>&gt; I would NOT warn the end users about needing to upgrade<p>People using your product are discussing it on review sites, on social media, with friends&#x2F;family, etc..  If you silently give some of them a broken product, a few will contact support; but I imagine most will assume your product is just low quality.  So that&#x27;s the word they&#x27;ll spread.<p>For corporate users: well, you&#x27;d need to talk with your customers.  They might be facing a seriously expensive upgrade process, and could be extremely unhappy to hear you&#x27;re setting an arbitrary deadline for them.