I think the term All Time High (ATH) is misleading as the All Time bit of it implies both the past and the future - and, therefore, there can only ever be one All Time High and it can only go down from that point. Accordingly what we are hoping for is not actually the all time high, but rather the next new high.
So I think we should stop using it and instead we should use the term High to Date (HtD) or perhaps World Record High (WRH).
High to Date is definitely my preference.
Note, this is not a wholly serious suggestion ... though the all time bit is slightly annoying ...
I understand what you mean however taking into account that we do not know what that level is then it makes sense that whenever the term ATH is mentioned people think on the highest price we have seen yet, pretty much everyone assumes that as a limitation of the term itself.
Also since that is the way most people refer to that level then I think it is going to be impossible to change it, just as that legendary topic created by GameKyuubi in which the term
HODL was born, we know the correct way to refer to it will be hold, HODL was a misspelling of the word but since then it has been identified as a way to uniquely distinguish those that hodl cryptocurrencies so I doubt the term ATH is ever going to change.