As Sam said they are still trying to work out how they are going to work together. He may be in the leadership team once those discussions have concluded
Or equally likely he's on his way out? If there is doubt about whether a person of his stature belongs on the leadership team or not, it seems to signal that he won't be on the leadership team.
To me the way it's formulated in the press release sounds a lot like what is usually said of someone on the road to a "distinguished engineering fellow" role - lots of respect, opportunity to command enough resources to do meaningful work, but no managerial or leadership responsibilities.
If they don't throw him out, I'd say the only explanation is they don't want one of their best researchers working for someone else.
That is exactly the purpose of "distinguished engineering fellow" roles.