While I see where you're coming from with a lot of your points, My opinion still is the date is meaningless information and won't make a difference especially to these 'less techy or casual users'
If the majority of these users don't even care to upgrade their Computers Operating system or hardware than what relevance would seeing a date actually make?
A unique version number is more distinctive and with certain people making videos about new games or things in MAME in version 0.1XX seeing the differential in the versions will prompt more casual users to update rather than seeing a date.
In reality people see dates everywhere. They see it on their bills, forum posts or social media, etc. etc. etc. This information is easily disregarded and omitted with the casual users thinking to themselves "It's only been a year or two and it's not worth the trouble. Everything I want to play works fine"
I'm inclined to believe casual users would more likely update based on version number rather than seeing a date, especially if they see videos or read about progress that tempts them to update because that information will be represented with a version number rather than any specific date.