Hey, I've seen this topic before!
Short answer; we'll have it for the premier league with KR, JP, and current APAC (SEA, SA, and OCE) teams competing.
But for the Tier 2 teams? No. People don't realize that you already can see the current Challengers system in APAC as a relatively more bigger regional leagues. People often underestimate SEA's size and subregion. 6 subregions with hundreds of teams lying in wait for their chance at glory. That's thousands of players too.
It's a much complicated situation compared to EMEA and the playerbase is much more intrinsically tied to each subregion. National pride is such an important thing here (and everywhere else,) but more so considering that APAC regional Challengers holds more weight rather than EU's Regional Leagues.
At the top, I agree, not completely, but it'll give quite the insight into how APAC+JP+KR teams will compete on an even playing field (2021 APAC LCQ was a mess.)
But for Tier 2 below? Subregion will have a place, and regional leagues will ensure that more new talents will arise.