The Philippines weren't ever connect to Asia via a land bridge and Huxley's modification of the Wallace line (Huxley Line) runs between the Philippines and Borneo [1].

This paper is very interesting though as it provides clues as to how the Denosovian spread through the Sahul. It adds even more support that the new homo sp. found in the OA are Denosovian.

1. https://en.m.wikipedia.org/wiki/Wallace_Line