This class is deprecated in core. If you need to know if the surface is "enabled" you can use .ve-ce-surface:not( .ve-ce-surface-readOnly ).
Looking at the actual use cases, I think the -enabled part is not required, and was just used once then copied around:
Code search:
https://codesearch.wmcloud.org/search/?q=ve%5C-ce%5C-surface%5C-enabled&files=&excludeFiles=&repos=
Change 932264 had a related patch set uploaded (by Esanders; author: Esanders):
[mediawiki/extensions/VisualEditor@master] Replace ve-ce-surface-enabled with ve-ce-surface
Updated about 90 gadgets. I don't have access to https://test-commons.wikimedia.org/wiki/MediaWiki:Vector.css though.
Change 932290 had a related patch set uploaded (by Esanders; author: Esanders):
[mediawiki/skins/BlueSpiceDiscovery@master] Replace ve-ce-surface-enabled with ve-ce-surface
Change 932291 had a related patch set uploaded (by Esanders; author: Esanders):
[VisualEditor/VisualEditor@master] Remove deprecated ve-ce-surface-enabled class
Change 932290 merged by Dvogel hallowelt:
[mediawiki/skins/BlueSpiceDiscovery@master] Replace ve-ce-surface-enabled with ve-ce-surface
Change 932291 merged by jenkins-bot:
[VisualEditor/VisualEditor@master] Remove deprecated ve-ce-surface-enabled class
Change 934398 had a related patch set uploaded (by Bartosz Dziewoński; author: Bartosz Dziewoński):
[mediawiki/extensions/VisualEditor@master] Update VE core submodule to master (ba83e8451)
Change 934398 merged by jenkins-bot:
[mediawiki/extensions/VisualEditor@master] Update VE core submodule to master (ba83e8451)
Change 932264 merged by jenkins-bot:
[mediawiki/extensions/VisualEditor@master] Replace ve-ce-surface-enabled with ve-ce-surface