Question: Will 1.17 be getting some height changes?

About 4 months ago, the YouTuber ibxtoycat upload a video titled “1.17 Can Bring Deeper Oceans, Nether & A Higher End!?”. Is this true? Will 1.17 be getting higher and deeper world limits? The first part of 1.17 didn’t seem to bring any height changes at least on Bedrock, but do you think these height changes might come along in the 2nd part?