Once again, for the slow children in class: They're not going to touch any the old beta designs and certainly not any of the ones they showed off in some form or another over the past 26 years, as they've already admitted they had stopped actively trying to make the design work.
EVERYTHING they add to the roster is made in part to sell toys, they don't show off something they feel they can salvage, turn into something to make money off as that's just wasting the potential idea. The fact the showed off the beta designs proves they can't make them work for the series and likely had them on the shelf since Gen 1 (their style changed by GBA, when they got a deeper colour palette, then again in Gen 4). They also don't give a fuck about weeb 'tards nostalgic for an era of pokémon that never existed, save in their delusions.