Did you ever find out the answer to this, Joyce? I tried the latest MM today and also got the 'processing official patch'
It was my understanding that it wasn't supposed to do that now?
ETA: I also had to up my official patch number in order to play the dlc (my merged patch is now at 12)...does anyone know if this is going to have consequences in the future?
The only time it's worth upping the patch number of your patch_modmanagermerge folder is when a new patch comes out that breaks modding and you need to override it.
That is, if Mod Manager cannot merge with the new patch, you can merge with a copy of the old patch (if you still have it or download it) or use an existing merge and then up the merged patch number.
If you do it any other time, then play the game, your save will be tied to the higher number. This isn't so bad when patches are constantly rolling out but the Patch Beta program has ended and I'm guessing there will only be one more patch (patch 10 - numbered 11) before the final DLC.
I'm wondering why you needed to up the official patch for The Descent. Was it because it you had to play it without mods? If so you probably wanted to lower the official patch number again before remerging your mods so that the numbers were all in sync again.
The numbering of the patch isn't a massive deal but it can make your saves unplayable unless you're prepared to keep fiddling with the numbers.
The new mod manager still processes the official patch if it's new and as you increased the number, it thought it was. It shouldn't do it every time you merge though.