There's no guarantee of that. And even if they do, that figure wouldn't see the light of day till 2022 or 2023 at the earliest but that's only if it's announced it in the next few months. The later it’s announced, the longare it’ll take.
If he or anyone else is able to find the figure for a high but not outrageous price and they have the means to pay for it, then it's not an automatic better to wait scenario. They could enjoy the figure now rather than years from now.
And it's not like it's going to be worth nothing if they sell it in the future after a Hot Toys ARC Trooper is announced. Sideshow completionists, customizers, or people who also want the the figure sooner would buy it. Or they could keep both. I don't plan on selling my ARC Troopers even if Hot Toys makes one.