I've reached out to some afterwards and offered help (serving as a reference, reviewing resumes, connecting to people, etc.) but in _that_ moment you should say as little as possible give them space to process emotions however they will.
I've had to fire people a few times. It's never fun, it's always been a hard decision that I took for the benefit of my team. It's never "bullshit". If it is bullshit then it would be MY job as manager to fix it and stop it being bullshit.
I've never had a negative reaction to the firing from the team members who remain. If anything, the reaction has always been "why did you wait so long?".
But luckily I've never had to do a team downsizing because of budget cuts. I imagine that would be a more difficult process and managing the emotions involved in that would be difficult. I see entirely why Coinbase chose not to take any of those risks and just cut everyone off first and then answer questions later.