Radmandoes this hold true for higher level teams?
No, when I die with bpm, if I am confident that I put out enough damage/got enough picks/need to use our uber advantage/got the right picks(med / demo / heavy / sniper each of these have a clear role in a fight. Med goes down, play it slow with your heals, sniper goes down, play aggressive with your pick classes and try to fight a spam war, etc), I will call the push. The heals I normally get will be moved to the engy or scout. On a lower team, this probably would not work because let's face it. It's pretty hard to miss as demo and when your hitscan classes are all missing a third to the majority of their shots, they won't be able to cleanup and they'll just die. Again, it's a call based on trust and judgement of the situation. However, if you want to play safe you should wait for the demo's spawn or only push when you have significant advantages.
tldr: If your teams dm is good, you can probably just out dm the other team based off of having more health or having more players. If they decide not to fight, congrats you just bullied another team out of a point. (most of this only applies to the 5cp maps, demo is pretty much needed to take down a sentry + force uber on PL)