Why assume the Animorphs died? Elfangor and his crew survived ramming the bladeship.
g already mentioned the Ellimist in the Andalite Chronicles. But I just wanted to expand on this, because I have it on tap.
Even if you choose to take the Ellimist out of the equation, Elfangor was surrounded by Yeerk and Andalite ships. So lets just say that he crashes into the Blade Ship that one time, and enough of his ship survives that he can breathe for a little while; there were other Andalite ships there to come to the rescue.
Jake, Marco, and the crew of The Rachel
found the Blade Ship in the middle of a part of space that the Andalites
are so afraid to enter that one of them had to become a nothlit, just so he could help them find Ax's ship and avoid violating the treaty with the Kelbrid. When they finally locate the Blade Ship, there are no other ships with them. There are no planets nearby, or at least none that we know if and none that necessarily support human life. They're in the middle of space.
And Jake's orders were to "Ram the Blade ship." Not, "Gently tap the Blade Ship." Not, "Hey, we're going to Denny's, ask the Blade Ship if it wants anything."
"Ram the Blade ship" isn't terribly open to interpretation. We can safely assume that if orders were followed to the letter, that one spaceship ran headlong into another. Either the Blade Ship was powerful enough with the help of The One to survive the impact, or the Blade Ship was suitably damaged. Either way, the balance of probability suggests that it is very unlikely that Jake and company survived, or if they did survive, they definitely won't make the return trip to Earth.