It shouldn't be a problem for buying or selling, as no one should buy something without looking at it first (in person or in a photos). If they do buy unseen, than that's their fault. The name or labelling by one person is not a factor for purchasing, as it could be claimed that listing "Optimus Prime" could mean any version of Optimus Prime... and it is the buyer who just has to take a gamble on what they get.

The confusion however, relates to reference, listings, and discussion.
Ever since Generation 2, Transformers lines have been given abbreviations by Fans for convenience in listings and discussion, and Japan have always given product numbers... so there is an element of confusion in those instances, especially when fans try to agree on what to abbreviate each new series - like Animated for example. TFA was already taken (unofficially by Fans) for Armada, so then there was this long period of fansites trying to designate a term for Animated, and even retconning Armada as ARM instead of TFA (among some fans) so that Animated would be ANIM. But in the end, there is now no consistent term for each series after multiple possibilities emerged, and vocal groups support and use each.

For the minor lines, it gets even more inconsistent, because they were less important to worry about. (less discussion and listings meant it was less likely to need abbreviations just to make it easier)
The more common a line or series is, the more demand there is for acceptable abbreviations, and for the two Masterpiece lines, it was easy having one with product codes (MP10 etc), because if they were well known ones, it was obviously easier to just use the code among fans who are familiar with it... or in text when it isn't necessary or possible (if there is a character limit) to use the full names.
And what if you want to refer to the second mould version MP Convoy, you actually need to use the MP numbering, or else it could be confusing.

Ultimately, more details the better, and that's something I heavily recommend for here to avoid confusion and hostile responses for misinterpreting it... but I accept that we are in an age when txting has conditioned many of us to use, and expect, concise-as-possible (abbreviations where possible - or else it is either too long to send, or too much to bother reading).



Just do your best to include as much details as possible to avoid confusion from others, and you won't have a problem. And if someone else is being too "brief", especially if selling, just ask for clarification before jumping on them.