[Tenoke]

They are offering this only for this year's Iphones and at some point this year's Macs. It doesn't seem like you can get a battery for 3-5 year laptops nor that you'd be still be able to get a battery for this year's laptop 3-5 years from now.

[Hamuko]

That probably remains to be seen. I imagine batteries are one of the most desired parts that they're going to make available, and assuming that they put a healthy Apple-sized margin on the prices, why stop selling them after a new product comes out?

[Tenoke]

It's possible but the reasons not to would be because the margins on a whole new device are larger and because carrying and producing old parts has costs.

[Nextgrid]

Don't they still offer battery replacement services for those devices? If so they're already bearing the cost of producing/carrying these old parts. In fact, they could potentially make more profit selling these parts by themselves to end-users considering how much demand there is for things like batteries.