Those changes haven't literally just hit, we're nearing 3 weeks at this point of Lux having gotten her nerfs. A patch worth of time is typically the amount of time it takes for Riot to look at the changes they've done, and see how things settle. You know what Lux support's winrate is at? 48.6, and that's saying something considering a majority of Lux's play her down bot as a 'support'.
The champs was just top tier support, let the changes you JUST DID settle and see where it needs to go.
No. People gave Riot so much shit when they nerfed Sejuani, and then left her in that state because they wanted her to 'take a break from the spotlight' when she was absolutely huge during the Tank Meta in season 5. This is the same logic, that you should hold off on buffing a champion because she was previously high tier, even if it's not to the same severity.
The changes have settled. Lux did not receive any major gameplay changes that actively change the way she plays, just number nerfs and a slight change to her Shielding application, so there is no real reason it takes people more than a patch to adjust. This post is just pure bias against Lux, with nothing to back it up in terms of argument or facts. You just don't like Lux.