Yes, all betas are date-bombed, which does make sense;
It avoids people using older betas which might contain known issues.
Using the GS911Downloader & the GS911 hooked-up to your computer, you can always download the latest version via the portal, including also the non-beta and so on.
Please bear in mind that every GS911 beta I have seen so far, states
"This is a Beta version and will expire on (date)"
below the version on the top of the 1st screen.
My practice is to hook-up my GS911 about a week prior to the beta expiration-date and check if a new version has become available already.