We announced at Ignite that we are actively working on bringing dynamic plus aliases to Office 365.
To get around existing usage, the plan is for an opt-in setting. Our ETA is to have this available for all customers by the third quarter of 2020.
I will keep you updated in Uservoice on our progress.Mikael commented
I would also like to have this to sort mails in receipts using a forward triggered by having a invoice+ in front of my usual mailaddress.