-
It is still apparently being investigated by the Conservative Party, just not the cabinet office. I'm not sure if the cabinet office normally investigates misdemeanours of all MPs, or only those ones with official government roles.
The fact it is still being investigated is generally glossed over in the reporting, in favour of the headline that the cabinet office has dropped it's investigation.
Regardless, I think the chances of him losing the whip on this is around zero. Police aren't taking it further so he'll get a public slap on the wrist, but nothing further. As shameful as it was, nothing will come of it.
On the Tory 'majority' ...
https://www.theguardian.com/politics/2019/jul/29/boris-johnson-drops-investigation-mp-mark-field-manhandled-protester
Assorted weasel words:
It's not really just about whether or not be's a minister.