You mean like Oracle with MySQL? At least in that case the 'community' could move to MariaDB, which is not an option for non-Free databases like MemSQL.
If MySQL was a drop-in replacement for MemSQL, you wouldn't need MemSQL in the first place. The reason you chose MemSQL is probably because it offers something that MySQL doesn't. If I can't take the source and continue using the product, it's a very different situation from MySQL/Oracle.
