I've just tested MP 18.104.22.168 build 1.1.6210.37535. Both "bugs" remain:
1) The \r\n is still on the last string in each XXX_label.
2) It looks like all data has been converted, not just MSG, to cell-arrays. This not only greatly increases the file size, and slows the process, but it looks like the indexing isn't done right, so the .mat file only has the last data of each type. (perhaps every write is overwriting the previous, not appending it to the data?)