Correct. 9 is happy to read tab delimited files but it always exports a CSV. See this topic.
A few weeks ago I sent in a Suggestion recommending that options similar to those for File - Create - Data Source on a csv, such as list delimiter character, be made available for exports, but it seems nobody else cares about that.
Personally, I don't know why people are so disinterested. I suppose they think you can always replace , with a tab, but that's a hassle if you have commas within text fields too. Or, perhaps, maybe with the rise of greater database sophistication in GIS people have moved on to GPKG or other formats that are far better than csv, so that's what they use, writing to those from 9.