The use of the future continuous when there is no reason not to use the simple future is both awkward and needlessly wordy, though it's more in the class of things (in a programming analogy) you'd catch with a linter than the kind that throws compiler errors.
I honestly don’t believe anyone would look at the phrase “we will no longer be supporting X” as awkward. The meaning is immediately obvious, and the construct is used frequently. Calling out a trivial style problem like this in a technical review is amateur.
