Speaking only for myself but I do not believe Revolution Education (Rev Ed) have a publicly available End of Life Policy.
Keep in mind that Rev Ed purchase hardware from Microchip (PIC’s), Devantech/Robot Electronics (Ultrasonic and multi controller Servo boards) and other manufacturers, Rev Ed are constrained and only able to sell a component/part while those suppliers continue to manufacture a given part.
How much notice do some of these companies give Rev Ed? (Microchip do by notice on their website, but what about oithers?)
There was a case not too long ago when Devantech ceased production of the SP03 speech module due to the primary Winbond WTS701 speech chip no long being available.
Rev Ed did advise when their stocks ran low.
If you go to the Rev Ed Datasheets webpage:
http://www.picaxe.com/Datasheet-List
At the bottom you will see they still provide the datasheets for obsolete modules that they no longer sell – usually due to non availability of modules/parts form other sources.
While Rev Ed may no longer sell earlier PICAXE chips as order volumes for the older chips drop when new chips come out, they are still supported by Rev Ed staff and members (to the best of members abilities/knowledge) on this forum when technical questions arise.
M2 parts are ostensibly drop-in repalcement for older M and X parts and also provide new/enhanced capabilities
X2 parts are ostensibly drop-in repalcement for older X1 parts and also provide new/enhanced capabilities
So you can in general use a newer part to replace an older part.
The current Programming Editor Software PE V5.5.6 still supports the older chips.
Can you indicate why you ask this question on EOL policy in the first place?
That might help others focus their answers more directly to you requirements.
Do you expect a written policy some thing like this:
General Example:
http://www.arubanetworks.com/support-services/end-of-life-products/end-of-life-policy/
Microchip for PIC:
http://ww1.microchip.com/downloads/en/Quality_ReliabilityDocs/EOLpolicy0809179.pdf
Devantech: no policy found
Why would/should Rev Ed stop selling a module on a date published 6 months earlier? Stock may run out earlier and cannot be re-stocked. Surely they are allowed to sell of remaining stock of a more expensive module if some remain and someone has a need at a later date.