Well, everything I have found on the subject seems to indicate that the NRTL listing for all products previously tested by Wyle Labs is still valid and has not been revoked in any way, which would make sense.
Only WYLE Labs themselves are directly affected by having their NRTL recognition revoked by OSHA as of August 24, 2011, but all equipment that was approved by them as an NRTL before this date is still valid and acceptable for use, just as it was before this revocation occurred.
Here is a statement from OSHA:
OSHA/Wyle Labs The last paragraph states "The DATES section above provides the effective date of revocation. Consequently, the Agency no longer accepts product certifications made by Wyle on or after this effective date."
Products certifications from Wyle Labs made after August 24, 2011 would no longer accepted by OSHA, but according to the interlockit website, those interlock kits were tested in 2005 and revised in 2009, so are still NRTL approved and recognized by OSHA.
Interlockit Testing 
