This is a moot argument...of you're playing a game before release date, especially now in the days of day 1 patches, then you're playing a game that is not intended to be played yet. This holds especially true for a game designed like BMS where everything relies so heavily on algorithms that work to generate the universe...
Why is it not your right to play a game you paid full price for? Also what if your moving house, starting college or several other reasons for being offline? As soon as you do that first update wham potentially hundreds of hours gone
You're in the process of moving into a new house, or moving into your dorm at college, and don't have time to get your internet up and running...BUT, somehow had time to put hundreds of hours into a game???...hmmmmm...
Idk when the last time you moved was, but you generally have things like phone service, internet, electric, gas, taken care of before you move so that everything is up and running either before you move in, or very soon after...
Also, what college have you ever been to where you would be waiting hundreds of hours before having access to the school's network?
No it's not..you shouldn't be playing the game before the release date...
But for something that's only listed as a single-player game, there's probably hardly any MP interaction at all so unless there is a ranked system or something, it makes little sense.
In this case though the way the entire universe is being created is being altered...so all the things you have "discovered" in the "old" galaxy no longer actually exist...it makes sense that it would break old game saves...
Now if 6 months, a year from now they change their algorithms again, and it breaks saves...THATS a problem...