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.Tim Phang commented
As an exchange admin you can set this up for specific addresses. Follow the instructions in:
https://durdle.com/2015/01/11/office-365-email-suffix-matching/ and change the match rule in step 6 to be something along the lines of:
This will catch "email@example.com" and redirect it to the appropriate mailbox. This will need to be configured for each user who needs the functionality. For a team of developers to be able to use for testing, I'd recommend creating a shared inbox and applying the rule there.