Is TimeShift on gog fully updated?

Depends what you mean.
As far as I know the last official patch for the game took it up to version 1.2
However the GOG release is 1.02, though it is a "re-release" so they may have started again with the numbering.

Are you asking does the game work on modern systems?
Well it still has the problem with hyperthreaded processors (Intel i3 and i7's) so will still crash if that is enabled. GOG support offered no fix for this other than disabling hyperthreading.

Are you asking if the game is updated like a remaster e.g Modern Warfare, better graphics etc?
This I can't answer at the moment. But as I have nothing to do today I was planning to finally disable my hyperthreading and get my Timeshift on to finally finish this game, so I might be able to answer later. From the screen shots it looks graphically the same, on par with Singularity (awesome game) so a 2010 release.

The Steam release is not fully up to date, it is lacking the latest patch. I was wondering if gog got the latest patch.

And holy crap the game does not work on CPUs with SMT. Ridiculous, this game is from what 2006. Disabling hyper threading is unacceptable.

Could it work in a virtual machine?

I don't think so I tried it a while back before I knew it was the hyperthreading causing the problem. I thought it might be Windows 10 or being 64 bit so ran a 32 bit Windows 7 in virtual machine but couldn't get it working.

I was think that in a virtual machine you could assign core 0 and core 2 to the virtual machine to get around the hyper threading problem. I am guessing the hyper threading problem may be that the developer foolishly locked the game's threads to the first two hardware threads.

What is hyperthreading and how do I desable it?