'Guys, we're losing the thin bevel design race ... and we need to try achieve the golden front-is-all-glass look. That means that Touch ID and the home button needs to go - but we'll implement something else called Face ID. What we'll do is tell the fans that Face ID is much better and they'll just follow without asking and write off Touch ID as rubbish.
Later on, we'll bing Touch ID back either under glass or even in a button. We'll just tell the fans that this is a better, faster version - and they'll be happy again. We can tell thm when perfected it.
But as we still sell the iPhone SE based on the iPhone 8 with a home button, we fon't nee to change that at all. As long as we've already paid off the tooling at the factory, we can keep producting these based on old designs'