that model just recently replaced the M401, so I would expect to see it actively sold for the next year or two- then you can expect toners and some parts to be available for at least 7 years, toners and rebuilt fusers for 10-15 years or as long as they are enough units to warrant continued consumable production.
The printers will probably go for about 150-200k engine cycles before the fusers fail. The most I've seen a M401 series go to is 300k counts. At that point it will be cheaper to replace the printers, as the cost for a tech & fusing unit will cost more than a new replacement model.
I have around (70) M425's/M401's in service for various managed print customers- those go to an average of 200k probably, and we replace them with M402's- we've also recently been upgrading 2430's to M402's with extra paper trays- and they seem to perform well.
I am not a HP employee. I am a service tech on these forums researching topics and offering my best guess to aide in your troubleshooting.