Hi
I run OpenSensors.io (focusing on open data in IoT) so my view comes from this standpoint. We already have a few TTN projects working to make their data open but would suggest that this is done as an Opt in rather than default.
The commercial considerations are interesting, we enable everyone that does open data projects to use it for free which means that maybe commercial orgs will use data to build further services. I personally am comfortable with this as I hope this also encourages the commercial orgs to contribute data making it better for the community. I can see the same working for TTN, commercial orgs investing in the infrastructure and building an ecosystem around it can be a good thing as long as all participants also benefit.
Just my 2 cents, will be looking closely at how the open data side will work generally at TTN as it's a passion of mine.