This is half true, but as stated false.
Geoff did not say it would be too hard to implement, he said, regarding res being an earned non-ult single-target ability: i think its a bit too complicated, we've intentionally avoided doing stuff like that in the past - On my stream I have verbally repeated this quote, stating he said “it would be too complicated”. I do not believe I have ever said it would be hard to impliment, which is a much different issue at hand.
Which, personally, I think all these changes seem to be very simple to test if they wanted to, and wouldn’t require any new assets to be created besides a new UI element for the res charge meter.