The core plugins have jumped from
PlatinumCorePlugins_1.0.0.7
to
PlatinumCorePlugins_1.0.0.10
(unless I missed some releases, but they're hard to overlook)
 
Why the change?
What's new?
(and what does this file contain, anyway?)

Hi. I believe TH3 is now included in the core plugins.
All the best.

But TH3 was originally in the Boutique Suite. 

Also, the updated Boutique Suite has been reduced in size by the same amount that the Sonar core installation file has been increased.

In Win10 I lost 150+ plugins after the 2017.08 update. One was my Sonarworks Headphone Ref3.
I had to re add C:\programs\VSTplus to the VST scan and rescan. Got them all back.  Something about the same happened with Win8 but I have no idea what happened. I'm thinking I just needed to reboot the computer.
 

Over the past 6 updates the Boutique FX Suite has waffled back and forth in size.
 
1.0.0.11    6/30/15    74.9mb
1.0.0.17    10/19/15    35.3mb
1.0.1.11    4/26/16    238.3mb
1.0.1.16    6/22/16    236.1mb
1.0.1.09    6/1/17    237.3mb
1.0.1.20    9/7/17    35.3mb