* BO rocket 2x the cargo size * Satellites same size/weight as starlink
120 sats per launch(vs F9's 60). If they have to launch 1618 by 2026, that means they need 14 launches in 6 years.
If they only need 1/2 the 1618, they need 7 launches in 6 years.
So I think 7 launches(840 sats) it's still in the realm of possibility, but they have to execute everything pretty much flawlessly to make it happen. They can't afford to have many things go wrong.
Getting 14 launches done in 6 years would be very ambitious. Unless they are way way further along than they have told the public, this is probably just wishful thinking.