Amplifiers with Thiel Speakers

 I wouldn't read too much into such things. At most shows, manufacturers let local dealers provide gear as they see fit. Much easier to fly unencumbered. Local dealers may have alternate agendas geared towards their local markets.
 New jobs opportunities may arrive from old job acquaintances, but don't necessarily signify loyalties to old bosses preferences. 
 Bryston was often used with older Thiel's, but the later versions like the OP CS 2.4's  with their sub 4 Ohm impedances became more difficult for many Brystons to deal with. Very few amp manufactures complete lines can handle such loads comfortably.

The late Jim Thiel was a big fan of Bryston Amps. Used them at many shows. He had a good relationship w/them. It was no surprise that Gary Dayton ended up w/Bryston after the downfall of Thiel.

Back around 1997, when I moved into a new house, I started off with Thiel 2.3s, then 7.2s and now 3.7s (got them when they first came out).  I had a huge room in the old house (19 foot ceilings and opened into other spaces and probably was over 7,000 easily with everything it opened into) and an integrated AV system.  I started off with a Rotel multi-channel amp and processor and it really didn't handle the 2.3s (I had a Thiel SCS2 center channel) with enough current.  I then went to a Bryston 4BST which could be taxed to its limit particulary on intense movie scenes or dynamic music.  I then went Proceed HPA amps (basically scaled down Levinsons as that was within my budget) and a Proceed AVP processor.  Then I moved on with other processors and sets of amplifiers.

I currently (since they were out) have an MCS1 center to got with the 3.7s along with 2 sets of SCS2s (for side and back surrounds), Power Points for front height channels and I have Axiom Audio in ceilings for rear Atmos speakers.  I got tired of expensive processors way back and went to a 2-channel preamp with HT Bypass (Modwright LS36.5DM) and get refurb receivers (capable of handling the center and surrounds - had a 3 channel amp for a bit though) at accessories4less.com for everything except the left and right channel.  It works well and I don't need to worry about changes in surround sound.  I have multiple systems and just rotate receivers to upgrade another room.  My main system is shown under my profile.

I have the option to purchase a Pass Lab X5 amp. What will be the best choice for HT processor to go along with X5? I heard great things about EAD. Apparently, there is not much said about EAD-Thiel combination. What is the reason?

I don't think the Rotel amp provides enough current for the Thiels 2.4 to sound their best. I am using a Levinson 27.5 with mine, and I really think I need to upgrade to a 332 or 334, at least. Thiels in general need as much power and current as you can throw at them. I have also heard Pass Labs and Theta sound good with these as well.

Theta Digital amps sound great with Thiels, and Thiel has used them at several shows.

Musical Fidelity likes to use Thiel when they demo their products to people.

Levinson 331/334 at least, 333/336 the best I have heard with Thiel.