No problem flying on tickets bought with former status
 

As we expected, the benefits of the "Works bundle" apply even if you no longer have the status that got you that bundle for free. I was a 100K an flew Frontier today and everything was the same -- except it didn't display my elite status on the boarding pass. Which was funny because, for the first time ever, the gate agent boarded elites first! (I didn't mind boarding 20 second later).

This is good to hear! I'm flying in February and was nervous about whether they would give me a hard time about my status benefits.

I am very curious to see if not having Elite noted on your boarding pass was just a glitch this one time, or if this will be the case going forward. I like getting on the plane first so I can put my bag right above me, as I normally sit in row 3 Stretch. If it is not noted on the boarding pass, how is one to prove Elite status at boarding?

Flew yesterday. I qualified for 20k last year, and my BP noted Elite.

My wife did not requalify for anything after being 100k
Her BP also noted Elite.

If the ticket was purchased with "The Works" because that cost $0, you should have received priority boarding as part of the package. I didn't check a bag or have a carryon but was given a Group 1 boarding pass this past weekend for a flight I bought with 100K status in December.

Correct. Same for us.