Google has long offered the ability to use a secure connection with Gmail via settings or using https:// in the URL itself. Now Google has defaulted it to https connection.
I don’t know about the readers, but I always used secure anyway. You can still move back to http, but that would be very unjustified.
Google was concerned about latency issues caused with https, that’s why it was never defaulted, but now Google seems to learn that security it the topmost thing we need.