I noticed that the loli tag is now a "character tag", which I think is strange since it's a tag for characters that look like a "loli", and not a specific character named "loli". I'm wondering why it got changed

Any registered user can change a tag type. If a mistake is made (deliberate or accident) it can be corrected. We log the changes now so the user who made a mistake can be given a notification by the staff. A user who does this multiple times after receiving notices not to do this is essentially tag poisoning and can be banned by an admin for this.

I haven’t checked recently but “uncensored” was changed from an orange tag to blue while were at it.

That is correct. I was the person who did that. Metadata tags are for information about the file itself, not for the artwork. "uncensored", "censored", etc should be general, not metadata. If it's something you have to actually look at the artwork to see, it probably shouldn't be a metadata tag. Metadata is for stuff you could see by looking at its EXIF data, source link, artist commentary, file properties, etc without having even seen the artwork.

I've been using the "decensored" tag as well as "uncensored" on my posts to differentiate between a decensored post versus an uncensored original for my photoshops anyway, since strictly speaking that tag is probably more relevant, along with "photoshop" aliasing to "third-party_edit".