I think it is a negative, if only because it suggests that "the market" has decided bitcoin isn't private enough for mission-critical transactions. If we want bitcoin to be the best electronic cash, it should have sufficiently strong privacy that the market does not near-universally consider an alternative as superior on that dimension.

I doubt ecash is a solution, because if any mint were to attract DNMs as users the mint operator would most likely be shut down.

Lightning is also far from being private enough to serve as an effective replacement for Monero. It might be too strong to say LN will "never" be as private but it does seem to me like there are fundamental technical challenges that would prevent LN from being as private.

I think the best solution would be to improve base layer privacy of bitcoin, leap-frog Monero's (now outdated) privacy tech and go straight for zk-SNARK-based private transactions a la Zerocash. Or we could enable validity proof verification on bitcoin, then developers can experiment with privacy protocols on L2 and the market will pick the one that works the best.