Are straight up trivial questions considered unwelcome?
An example would be:
- Who is the voice actor of X in game X?
- What is the song called in game X?
They're on-topic strictly speaking, so long as they meet basic standards in terms of question clarity, etc.
However, there are many users who don't like questions of this sort, seeing them as not useful (see also: Lore Questions). Furthermore, questions like this are also often easily answerable with a quick google or IMDB search, which reflects poor research effort. Expect some downvotes.
A downvote doesn't mean your question isn't welcome per se. Downvotes are not meant to judge whether a question is on or off topic. They're meant to assess the quality of your question. It's a subjective measurement, and sometimes, people are going to disagree with you about what constitutes a good question. Unless you're getting more than 5 downvotes for every upvote, you probably shouldn't worry too much about them.
Those types of questions are on-topic (are allowed on the site). There was previously an effort by a user (or some users) to close all questions of those types as off-topic or 'not a real question', but most (or all) of those questions have been left opened or reopened by the community.
Some of those questions:
Downvotes are a very different kind of animal compared to close votes. Unlike close votes, people can downvote pretty much for any reason they want (see also: Lore Questions). To avoid downvotes due to what some users might see as "minimal research effort", you should include what you already found out when asking questions like these (e.g. what info you found through searching with your favorite search engine), and which info you found is unclear, or need clarifications or expounding on.
I think that if a question matches all 3 of the below criteria, it is off-topic.