FWIW: Polling showed American support for interracial marriages was still underwater in 1992, decades after the Loving ruling. Majortity support only happened on the mid-to-late 90s
You have a parlementaire democratie, so do I. It is not illegitimate for a democraticly elected official to do something within his legal rights that is against the opinion of the people. Doesn't matter wether he "lost" the election, he still won it more than you. You calling it illegitimate is more illegitimate than what Macron is doing.
Which is why he should refrain from acting such a strong policy shift and what could be perceived as a major change of alliance.
What would be equivalent would be Trump deciding to change a long standing geopolitical policy after he lost the mid-terms and without the US congress having any voice in the matter.
0: https://www.lepoint.fr/monde/exclusif-reconnaissance-d-un-et...