So Epic contractually committed to develop and support the RealityEngine for existing licensees
Artificial Studios will continue the support obligations, not Epic, hence the wording of the press release.
I am sure that would be more comforting for them if they had it in writing
Again, existing license agreements are contractually safe, as any licensees who read their paperwork will be aware. The licensor, whether Epic or Artificial Studios, cannot terminate the agreements.