This would happen every month, and ranged from niche titles to big titles. This is (or at least was at the time) a wide-spread complaint among Netflix customers. I know why they did it (because the fewer titles a customer rents, the more money the company makes. So they hate when customers rent a lot of movies).
The main complaint is that they did not charge extra for Blu-ray Discs until after Toshiba announced it was ending the HD DVD format. Up until that point Netflix let customers get Blu-rau Discs and HD DVDs along with DVDs. A few months after HD DVD ended, Netflix announced they would start requiring that $1 surcharge to get be able to rent BD's (BTW, that is the official abbreviation according to the Blu-ray Disc Association, not "BRD"). It's bad enough companies are screwing the few consumers who are actually interested in Blu-ray Disc (NO movie should ever be $25, yet alone the $35 some movies cost on BD, even $20 is too much for a movie).