"XXX is being investigated" implies there's some kind of possible wrongdoing here.
There might be some of that, but this is not likely the focus of the investigation.
They're investigating a potential influence operation involving the CEO, which may overlap with investigating some kind of culpability on his part.
It's an unfair editorial headline.
- edit -
Here is the literal source:
"" initiating an independent investigation in light of recent reporting that founder and CEO Jensen Huang has been the target of a foreign intelligence effort.""
Jensen is not specifically under investigation, if anything the language is sympathetic to him being the target of a foreign Op.
The US government is investigating Alice Huang (not Jensen) for obvious reasons.
Obviously the 'bar' is different for the CEO than for someone acting with criminal intent, but it's not far to say that Jensen is under investigation.