The state of your instructors technical knowledge depends on several things:
1. the regulatory set under which the course is run;
2. the type of course
3. the quality of the organisation/instructor running the course, and
4. the money paid for the course!
Many basic training instructors are happy to repeat the same thing year after year, but GOOD type rating course instructors do keep in touch with Base and Line maintenance changes - IF they can.
If the organisation/instructor is not part of an airline or maintenance organisation contact with new developments, specific modifications and other updates can be difficult and the course will start looking like old info eventually.
I have seen some courses run by independant (self-employed) instructors who get patronage due to their low cost - but these courses generally show the level of monetary effort too.
Either way, the instructor (or anyone for that matter) doesn't normally perform his job to the worst of his ability - it may be just what you've paid for.