In their current state loli and shota are awkward hybrid tags that people disagree on the definitions of, much akin to the erstwhile cub. The current wiki pages define them as:
A Loli [Shota] is a female [male] character who resembles and appears to be young. This phrase is used to refer to humans, humanoids, and anthros alike. * Note: This should only be tagged for explicit and sexually suggestive content.
In regards to gender shota does not currently imply male and people have asked for loli's implication to female to be removed (topic #40890). It seems that many people what them to operate similar to how brother_(lore) and sister_(lore) do (covering male andromorph maleherm and female gynomorph herm respectively).
In regards to form, loli/shota exclude ferals and taurs, similar to how cub excluded humans and humanoids. (loli ~feral ~taur -human -humanoid -anthro returns 12 pages of results, while young female -loli ~feral ~taur -human -humanoid -anthro returns 194).
There is also disagreement on whether or not loli/shota should be restricted to questionable/explicit posts (topic #28252).
Various other disputes and disagreements have been collated by Alphamule in topic #39572.
I am in favor of aliasing loli and shota away to young_female and young_male. Some cleanup would need to happen first (~loli ~shota intersex returns 24 pages currently (though intersex isn't always referring to a young character)), but I think it will be for the best in the long run, as those are the most agreed upon parts of the definitions and what people who are searching for loli/shota are most likely to be looking for (as a bonus, this would also give us a big leap forward in the young_[gender] tagging project).
Some people have said that loli/shota should instead be aliased to a blanket sexualized_young tag, or that they should be implied to it and a third, new tag be created for intersex and/or ambiguous characters.
The second option is a nonstarter, it doesn't solve any of the problems listed above and creates new ones. The first however, I think is only misguided. If that were to happen 99% of all young questionable/explicit posts would have to be tagged with sexualized_young as well, which is never going to happen. People are simply not going to remember to tag sexualized_young on something they've already tagged as young and explicit. This makes sexualized_young a useless tag for blacklisting purposes.
I would propose that we instead create a blanket nonsexualized_young tag to cover that 1% of questionable/explicit posts that are exceptions to the rule. We already have a few existing tags that are similar in concept, such as adult_on_adult and adult_focus. This would allow people to blacklist young -nonsexualized_youngeffectively.