There is NO debate because Joomla DOES NOT PROVIDE ANY ascending COMPATIBILITIES as they claim.
The problem is just do on the fact that they changed class name, move files on location, ....., that creates incompatibilities.
So every 6 month, people have to review, redo compatibility testing, ....
Joomla themselves display a message in the "Joomla Update" to remember the users that they must verify the compatibility of the extensions before doing the upGrade of the core.
This is the reason why, for several years, we recommend using the "Apollo 13" procedure before doing the upGrade on a live website.
see
www.jms2win.com/en/documentation/j-and-beyond-2013
This help identifying the potential incompatibilities and define the actions required to do the upGrade in all security.
The problem is that Joomla force people doing the upGrade to benefit of security fixes.
So this does not let choice to redo testing very 6 months.