Yes.
The FEB does not notify the PSB that the FEC has been cancelled (the SAFEA guy kind of chuckled when I asked him that directly and said, "Of course not." But then, they (SAFEA/FEB) weren't aware that the PSB was now taking this position so that might change. But I wouldn't count on it because there is some antagonism going on between the two organs.
Where it catches up with you is if you go in to the PSB to renew your RP (which will require a new/renewed FEC) and the date of the FEC is more than 10 days previous.
Ignorance of the requirement may or may not help. In my case (written up elsewhere here at the Saloon), I had to sweat out sitting across from the PSB guy while he went through his computer. I had explained to him that my old school and new school had cooperated together to get the old FEC cancelled (and a cancellation notice from the old FEB) and a new one issued all before school ended because everyone in both schools would be gone over the summer. My RP continued all through the summer. In the end, he told me I had broken the law, I was being given a "Warning" but that he wouldn't fine me (he made a specific point about this). And then after signing the warning, he allowed me to proceed to the RP desk and apply for a new RP, which I received yesterday. So I was blamed even though it was the new school that was pushing to get the new FEC issued before summer vacation started so when I finally arrived at the end of summer, we would just have to deal with getting the RP. This approach is no longer feasible under this new approach that the PSB seems to be taking.
In another thread here, babala reports that one of her old teachers had his FEC cancelled 6 weeks ago and when he went in recently to renew for his new job, he was fined 6,000 RMB.