There has been a lot of related topics over the years - in some form they have all evolved around being able to keep the system at a certain level, install the same set of packages airgapped systems or sync a system without internet connection.
The blunt and direct TL:DR
Probably not going to happen 
Likely not what you were looking for - you are the system administrator - you are free to handle it as you see fit.
Manjaro provides a branching buffer stable ← testing ← unstable, where unstable is equal Arch Linux stable.
This is likely why you are still in a sane state of mind 
regarding your question.
To keep yourself in that sane state - you have a couple of options
pacman.conf
The native package manager has an option to ignore certain syncs. Please see → pacman.conf(5) — Arch manual pages
This is a limited option and it shouldn’t be active for a too long timespan.
custom mirror
You can keep your system at a certain level by creating your own mirror - that mirror does not have to be public - you create it just to keep your sanity.
This option can be used for a longer period of time. It allows you to sync new packages to your system matching a status quo. To move the status quo - when your depending package(s) is in an acceptable state, then - to sync your mirror - you run the sync script described below - then sync your system(s) using your portable mirror.
Please see this following topic → [root tip] [How To] Create and use a portable Manjaro mirror