Which would suggest that at least that element of the article was guesswork/speculation.
Opensourcing (in whole or in part) would have several impacts.
1. Increased software development options.
2. Increased hardware development options (including the possibility of porting code to other platforms)
3. Remove development overheads from Castle so it can concentrate on its STB business whilst (possible) keeping a revenue stream depening on the RO licencing arrangments.
4. Put ROL in the tricky position of continuing (allegedly) to develop RO4 via Select, or supporting an Open Sourced version that is updated by a wider community.
Number 4 is probably of the most interest here (and links in with no 1), as it means that ROL could maintain a RO 'Core' build while managing Open Sourced projects for other parties. It remains to be seen if they would fork the OS.
I suspect there would be no more RO5 development per-say, and that the 32 bit version of RO4 would be ported to the Ionyx to merge the forks.
This allows ROL to control the full RO (ARM) market.
Sorry there's a lot of of 'ifs' and 'buts' in there, but its the most logical path (IMHO), should Open sourcing go ahead.