@hvelarde In the plone/app/event/configure.zcml you have this line
<include zcml:condition="installed Products.ATContentTypes" package=".at" />
maybe you can replace it by (not tested) :
<configure zcml:condition="installed Products.contentmigration">
<include zcml:condition="installed Products.ATContentTypes" package=".at" />
</configure>
Products.contentmigration will be installed (meaning available in python path) if you depend explicitly on plone.app.event[archetypes]