Here's the full quote for clarity:
Your designer is on a new design trend today. Gone are dishevelled UI and post-Material, this week's design follows the design trend "neo-modern interactive." You asked them what that means, and the answer was a bit confusing and involved emoji, but anyway, here are the mocks.
From the context, it looks like a general joke about the pretentiousness of designers from the point of view of Engineers and developers.
Phrases like "Your designer is on a new design trend today" and "This weeks design trend" hint at a fickle, changeable nature.
"Gone are dishevelled UI and post-Material" hints at frustration in the writer caused by designers who are constantly changing things.
"the answer was a bit confusing and involved emoji" is there to show us that the writer is not prepared to deal with what they see as pretentiousness.
Like you, I cannot find any reliable definition of the phrase "neo-modern interactive" which suggests that it does not exist. Neither can I find any trace of "Disheveled UI", and the only trace I can find for "post-Material" actually refers to the shift away from physical media into SAAS and streaming.
I think this is an important opportunity to understand the views that some developers/engineers have of design. This could come from having experienced a pretentious designer in the past or from anecdotes shared by other team members or even other disciplines.
Whatever the source, it shows how important it is to communicate clearly and intelligently with the people who are going to build your design - If they don't understand your choices, then they are not going to value those choices in the same way you do. Something that may be an important experience consideration may be deprioritised because it's assumed to be a bit of unnecessary decoration.
Make sure you talk to your developers and make sure you understand them too!