This is a feature of the game since it was released, meaning it is buried very deep in some modul of the game and wasn’t touched most probably for many years.
Do we really want that Ludia touches this piece of code? It is possible that there is even no one left who knows how it was implemented. We all witnessed the consequences (does anyone remember the frozen bug issue?) of minor adjustments that they do in recent updates. I do not want to imagine what will happen when they dive into the very heart of the game’s code.
I’d change the hatch times and rationalise them. It doesn’t make sense that the majority of the creatures in the game have 7 day hatching even though some of them are far more useful than others. I’d leave the high end tourney hybrids at 7 days and reduce the legendary hybrids to 5. Tournament creatures should be reduced to 4 and legendary ones down to 3.