Of course I cannot answer this question. I would not prefer zipped files due to security problems. Beside the zip bomb vulnerabilities, you can hide malware more easily in zip files also.
I've created a pseudo-zip file and attached it:
s = 'hello!';
Reading it works by:
Therefore I do not see a real benefit of rejecting '.mat' files.
By the way, with posting this file I agreed with the "Guidelines for Submitting Content". But this text is very hard to read. Such juristic texts are hard to follow in the mother-language already, but this forum is thought for international access. So I agreed with these guidelines, but I frankly admit, that it would take me more than an hour to understand them in detail.
Wouldn't it be necessary to post a definition or at least a link to "Creative Commons Attribution Share Alike 3.0 license"? Because I find the name of the license only, I have to trust the results of my favorite internet search engine, that exactly this version of the text is shown on top, which is meant by MathWorks. Of course this is likely, but for a legal text, which tries to be bullet-proof, more clarity would be more useful.