Yes the white dwarf merger scenario for Ia supernovae is still very much alive and I believe is suspected by many to the the primary mechanism. The empirical relationship between Ia supernova distances and other measurements of distance still seems to hold though regardless of the mechanism. It is worrying though that we are relying on a standard candle without a clear understanding of the mechanism.
A shameless plug here – studies of SN2018oh, which I classified, contributed to this Ia mechanism controversy though without any clear conclusion.
https://arxiv.org/abs/1811.09635
Robin