I think an important point to this topic is mentioned in Deprecation of Agile Development 2.0 and Migration to Collaborative Work Management (CWM) and EAP - ...:

 

• At the end of your subscription term end date
  The applications and plugins listed below will reach end of support.
  • They will remain active in your instance, including during upgrades
  • ServiceNow will no longer provide support, fixes, or enhancements

 

From my point of view the decision of customers will therefore depend mostly on the licensing offer they get for CWM and EAP.

If the price is too high, they will probably still using Agile Development 2.0 without suport, even after their current subscription term has ended.