$29.99 Battery replacement program

No. See the following from A Message to Our Customers - Apple

Apple is reducing the price of an out-of-warranty iPhone battery replacement by $50 — from $79 to $29 — for anyone with an iPhone 6 or later whose battery needs to be replaced, available worldwide through December 2018. Details will be provided soon on apple.com.

Also see the $79 price shown in iPhone Battery & Power - Official Apple Support

It's actually $29.00, but not for those models.

Apple doesn't do any throttling for those models. The newer models have smaller batteries and more powerful processors. Usually not a problem when routine throttling (and there is no way to be able to watch 10 hours video on one charge without it) is done, but can be a problem when peak current is needed, like opening up applications or some power hungry apps like benchmark tests.

If you really want it, there's nothing stopping you from going to an aftermarket installer or even doing it yourself. It's not necessarily simple, but it's not particularly difficult with the right tools.

iPhone 4 Battery Replacement - iFixit

iPhone 5s Battery Replacement - iFixit

TGeiszler wrote:

This leave a lot of iphone users of older devices out in the cold. Not a happy Apple customer. The new phones are priced way too high for someone on a fixed income. I’ve been an IPhone user since they cMe out. Their high prices are forcing me to go to Android.

Would you go to Android if the $29 price was NOT offered to those with iPhone-6 and above?