is there a "beta" BC explorer? or just "alpha"
aren't we on the "beta" wallet??
The version of the block chain explorer is alpha as written there
the data that you see there is data from the latest NIS-NCC.
The block explorer is a separate software developed by 2 developers
and NCC - NIS is another software developed by other 6 developers.
Software version is usually set by the developer of the software
that means if there were no changes in the code of the block explorer neither the version
of the block explorer will change even if the NCC - NIS changes.
So in case somebody else starts to develop his own software or mobile wallet or block explorer
the version of the software could be 0.1 alpha or 0.0.1 alpha of just 1 alpha or 1 beta or whathever the developer puts there.
I hope I made it more clear for the nemsters to understand 
if not you can find more detailed information here:
[url=https://en.wikipedia.org/wiki/Software_versioning]https://en.wikipedia.org/wiki/Software_versioning