You start with a promise of significant changes coming soon and finish by saying (in effect) Legacy app downloads can disappear as soon as those changes arrive. Which is simply a more positively phrased version of what's already been said. It's a bit like me saying I'm committed to losing weight until my weight changes. If the company is truly committed there should be no problem promising the Legacy app will continue to sync without new bugs through, say, 2021. But such a promise would in effect be supporting the legacy app, wouldn't it? So aside from a reaffirmation of the previously announced features to come, nothing's really changed by your post.
I'm old enough to remember when release notes documented changes in a product released to customers, not promotional statements about changes coming Real Soon Now. What in the world has happened to software companies these days?
No, that's not what was stated at all. There's no statement the Legacy app will be supported, merely a commitment to making it available. And for how long? I don't know what a promise to support crucial workflows means given the numerous reported problems with v10, but I'm pretty sure it's not "until we're closer to closing the feature gap".