Simple. Advanced Services used to do a lot of the higher end CS motion, and SE's most of the rest. MM bamboozled CR on the concept of CS, and how Cisco didn't have it, so he gave her a remit to fix it. Tech Support funds were steered away from TAC (now customers feeling that big time), into a big CS org, with TS leading the "product".
A huge song and dance, big noise, big launch of ST L1 from TS. MM, TS, too many - needed to cover up the fact that Adv.Svcs. were already looking after top customers, so none wanted to buy STL1 or STL2. CS dashboards changed monthly to massage the numbers, make sure adoption numbers went "up". TS has to make STL1/2/3 successful soon or he's out. First serious batch of renewals is about to hit since CS launched... moment of truth for the mostly behind the scenes accountants in the renewals org. New CX Product VP has been brought in by TS to "fix" PLM - going to be a blood bath.
Was there good stuff past few years? Yeah. BU's PLMs confronted by CX people asking "how does your widget make value for the customer" and cr*ping their pants because they had no idea... so they stalled and sabotaged their CX Cloud Integrations. But finally they are waking up to the importance, and actually starting to make products for customers, not what their VP's think will make sales VPs happy.
The miracle is how MM and TS have survived given the terrible performance of CS. Ultimately Adv.Svcs, account teams, etc. are still doing a lot of their jobs, and big accounts have power struggle between prof.svcs. and CSE. So still a big effing mess.