The Tigerair EBA does allow for redundant pilots to keep their place on the Tigerair seniority list for 5 years. It does not mention the greater group seniority list, and isn't written with redundancy of the whole pilot corps in mind.
Few VA Group pilots would bemoan the TT pilots keeping their place on the GDOJ list, in the unlikely event it's worth anything. For that you'd need VA to exist and hire pilots again.