they confirmed that when they were still on the 32bit limit. so it depends if they meant needed in a technical sense, or needed in a aesthetic/number comprehension sense.
i personally think they will not do a number squish, but instead go for the "mega damage" option. you can already see them sneaking in minor examples of htis with AP tokens that say "1 billion" intead of "1000000000" on them.
in true blizzard fashion they go "hey guys what about this idea?", everybody says "plz no", they go "ok", and then over the next 2 years they gradually put it in the game anyways and nobody bats an eye :P