Gelug Lamas are not sectarian period. If Ling Rinpoche was sectarian why would the holy Karmapa visit or be associated with him?
The Karmapa has already spoken and given the prophecy that one day everyone will be worshipping Dorje Shugden, and as Ensapa quoted Ling Dorje Chang has practiced all his previous life what more do we want?
In his current incarnation I have not heard Ling Rinpoche saying anything untoward towards Dorje Shugden, one can only either for or against, if he is against why not vehemently say as he feels and be open about it. Everyone related to the CTA seems to open about how they feel about Dorje Shugden.
Nevertheless happy to see Ling Dorje Chang is saved from a potential death and will be carrying on the spread of buddha dharma more and more.