Yes the redundant orgs will probably be mainly laid off eventually. You don’t need 2 HR’s, G/A, etc. Sales will probably be reduced quite a bit and the engineering team will stick around.
Every acquired company always says that, practically verbatim. It's meaningless, the CEO doesn't have a say anymore. Salesforce's designs are the relevant direction now, and they're not telling. Facebook (Telegram, Oculus, Instagram) and IBM (dozens of companies) come to mind as specific examples of acquisitions in which the former CEO insisted that business would continue as usual, only for the management teams to be gutted and the company culture eradicated.
We're still remarkably separate from IBM, just as was promised. I do find myself collaborating from time to time with IBMers but most of the time we're pretty separate.
Their culture is very different than ours so it can be interesting when we team up. I think Red Hat is having a big impact on IBM honestly. They seem to be really embracing Red Hat tech and culture. I was really worried when the acquisition happened, but I no longer am worried about it. In fact, for the first time in a long time I'm optimistic about IBM. I'm looking forward to see what they do.