The last jboss-as-web schema included in a community release is jboss-as-web_2_0.xsd

JBoss EAP contains both jboss-as-web_2_1.xsd and jboss-as-web_2_2.xsd

I believe something was mistakenly added to the 2.1 schema in EAP, this was forward ported to WildFly - then the change to 2.1 was reverted in EAP and a 2.2 schema added.

Version 2.1 and 2.2 of the schemas need porting from EAP to WildFly and the parsers updated to support them accordingly.