Yes. This is as bad or worse than Clinton's email servers. It deserves to be talked about at least as long and investigated at least as thoroughly. Which in the case of Clinton involved bringing it up for nearly a decade, an FBI investigation, an Inspector General's report on the FBI's and DOJ's handling of the case and a three year State Department investigation. It's only fair to apply the same standard here
We wouldn't know if a private email was configured similarly, or if emails on a private server were manually deleted.
Either way, yes using a communication system on the public internet and outside of official documentation processes is bad no matter how you do it. Deleting those communications could be a bad sign, though to be fair it could also be a sign of someone trying to do what they think is more secure (avoiding old messages being leaked or hacked later).
