So I actually tested this and it's so easy to escape to the point where I don't know why anybody would take anything SFP says seriously.
For entertainment value I'm not going to say how Bowser escapes it just to find out how much time it takes for SFP to figure it out.
Yes I just tested it this morning and he can jump out after a certain percent, something early like 20s, I'm not sure. The guy I was testing this with was my room mate and doesn't know the game very well, I just said "here, take this control and hit this combination of buttons." It wasn't a grand announcement or anything.
By the way, this is not tactical discussion where it's cool to make fun of me. A lot high-level tricks and nuances for ZSS have spawned here based on my ramblings (which are yes sometimes incorrect). For everything I get wrong, I get something right. The "breast attack" (forward bair) was something Nick Riddle actually was able ot make use of in his match at MLG. According to Dazwa, he yelled "thank you SFP" into the crowd. I also found dash attack locking and have done a lot of research on how certain moves interact with other moves, etc.
When you laugh at me for screwing something up, you just look stupid to the regular posters here because they know better.
There's a reason I posted asking other people to test it out and check my work before I got too excited. You can also do that chaingrab by just buffering a dash grab, as usual, and Bowser still sucks. So...