AFAIK that's not quite right - I'm not sure if Mr. Moore practices in this area or is even an attorney.
Let me preface by saying, I do a lot of reexaminations - what the PTO determined in the VHC waiver petition is that the Response was compliant AS FILED. That means that the clock for the reply by the third party started when the document was filed because it was deemed satisfactory retroactively.
So as a practical matter the third party cannot sit back and watch and see what the PTO will do first. You will note in the 95/001746 case that the oversized PO Response was filed January 17 with the petition to waive the page limit. The Requester filed their reply on February 15, even though there was no ruling on the petition to deem the January 15 filing compliant. This is SOP and good practice.
The third party can't wait for the PTO to decide if the submission is compliant or not. They have to assume that the PTO will deem the response compliant. In my experience, it is only if the PTO decides the filing is non-compliant that the 3PR gets another shot - if you are hoping for an exception, the PTO may not be very friendly and you may be subject to a malpractice claim by the client.
Now that doesn't mean that some folks might not try this tactic and see if they can get away with it. But as written, the rules don't allow the 3PR to take a chance on the PTO finding the filing deficient. The safer practice is to file the reply after 30 days - NO MATTER WHAT - and go from there.