The announcement from CoreCode:
CoreCode Ltd., the developer behind the award-winning MacUpdater software, today announced that it will be discontinuing active development of MacUpdater after January 1, 2026.
As promised, all MacUpdater 3 licenses will be supported until 2026-01-01.
After that date we will no longer continue to develop or support MacUpdater
but we hope to find some other company to continue the product or its technology:
It was a useful app. Sad to see it go
Sad. 
I am sure a company will buy this great product and continue developing it. But the question is: what will happen then?
Well, we will see …
Still is (until the end of the year?).
I hope they find a good buyer who will offer us fair prices (but I fear the opposite will happen).
Unbelievable loss to the Mac community. Unrecoverable if someone doesn’t step in.
300,000€ per year with a subscription
It feels like they were trying to grow the user base then monetize the app through a sale. It just doesn’t make sense. Most users like me would gladly pay $0.99 a month for an app like this.
Multiple by 10,000
The amount of work that this app to make and maintain is staggering: MacUpdater discontinuation, sale and licensing