Good to see you here for the first time. You ask a complicated question, luckily it has a rather simple answer 
Collabora is an Open Source company and all of our code is 100% open-source.
Also - we have no plans to change the license. While today TDF is behaving aggressively, it may be more reasonable in the future - there is always hope of future collaboration.
It seems there is benefit in keeping the door open for future reconciliation by continuing to use an compatible license. For now we will be doing our work, with our own focus in our own gerrit (cf. Distributed by
Design) but also contributing to LibreOffice where it makes sense; it is easy to over-think the change here.
I hope that helps
Michael.