Here is an article in Trains on the subject of this thread. An account may be required on the Trains website to gain full access. Though I'd place a pointer here anyway since many here are already Trains subscribers.
http://trn.trains.com/news/news-wire/2018/08/01-amtrak-changes-booking-policies-for-tour-operators
The main thing that is different from the usual shrill shouts on trainorder are:
1. Full payment is required 90 days before departure.
2. Cannot hold accommodation on trains on consecutive dates.
3. Specification of maximum number of Sleeping accommodation that can be held on a train by a tour operator.
4. More than one tour operator not allowed to hold accommodation on a train.
All these appear to be changes that should be friendly towards your normal day to day average user of Amtrak.
I cannot see what is there to be upset about this, unless you are a tour operator. The cost of doing business will undoubtedly go up for them. What impact this will have on revenues in general remains to be seen.
Apparently, contrary to what was reported on TO, Group Travel operators have not been removed. What has been removed is a special set of operators who exclusively handled Tour Groups. Now Tour Groups will simply have to do their thing through the standard Group Operators who also handle humble groups of passengers without a tour operator fronting for them.
Mods: Maybe the title of the thread should be modified to reflect the fact that the Group Desk was never really eliminated as alleged. For those married to the TO rumor mill, now there is even a thread there stating so in its title