Most TPM sellers make an effort to publish End of Life lists, that they make available on their website or send to you via e-mail. You should understand that those are primarily marketing and demand generation exercises and not something you should necessarily rely on for any important decision-making.

Many times they will list devices that are terrible fits for TPM, and they may not cover or actually offer TPM entitlements on the device. But they want you to contact them because even though that device is not a good fit for TPM, they would like to talk to you about other devices in your infrastructure estate that may be good fits for TPM.

Manufacturers/OEMs, on the other hand, tend to obscure their "end of" announcements and not make them easy-to-find or freely available. This is because their optimal sales cycle is dependent on them starting the obsolescence conversation with you BEFORE you start to think about it. This conversation is typically started relatively early in the device lifecycle and will be centered around how newer equipment is faster, more capable and more secure than the older equipment you are running. This is where your natural skepticism should be nurtured and you should question whether you truly need new equipment.

THE TYPICAL "END OF" MESSAGES THAT YOU SHOULD BE CONCERNED WITH:

End of Sale: This is typically the first announcement, as in the device is no longer available to be ordered through normal sales process. This basically means that the manufacturer won't take orders for it anymore and that production of it is ending.

End of Support: This typically means that the device is no longer supportable through normal maintenance or support contracts after this date. Many OEMs offer special post-End of Support support contracts that can be purchased at a premium. These are typically only offered to a subset of end users, typically large volume end users and never small users.

End of Software Maintenance/Updates: This means that the device software or firmware will no longer be updated or maintained past this date. No updates will be published. Typically any emergency security updates will remain a possibility if they are found to effect all end users. But routine updates will not occur.

End of Life: This published date means that after this date, end users are assuming all of the risk in operating and maintaining the device as the OEM has determined it to be obsolete or deprecated. This does not typically mean end of function, only that function as originally designed is no longer supported by the manufacturer and they will not open support tickets by any end user anymore.

Note that for some high priced enterprise equipment, manufacturers/OEMs will offer special extensions of support beyond End of Life at premium prices, typically much higher annually than the price of a maintenance contract when the gear was within support life. These expensive 'extended support' agreements tend to only be available to certain buyers and should not be something that the average end user can expect to take advantage of.