Talkloids are actually pretty popular in the English speaking fandom, there's multiple uploaded a day with Japanese-only banks being surprisingly some of the most used. I think so long as there are fans interested seeing the characters interact, they'll be excitement for speech-synths. I've even seen cover artists complaining that speech skits get more views than their musical works.
(I am not sure how to properly word this, so my reply will be awkward.)
In my mind, there are two types of Talkloid fandoms.
For English speakers: They make skits by using singing synths (ex: VOCALOIDs) and have Japanese-only voice banks speak in Engrish. They do not seem to touch actual TTS voice banks (ex: VOICEROID) due to the language barrier (interface only in Japanese) and it being less easy to edit phonemes into Engrish compared to in a singing synth where you can chop notes to be very tiny. (In TTS, you can basically only work with katakana). When an English-only speaking person buys a character who ONLY is a VOICEROID, they usually want to make them sing with Kotonosync and don't use it for anything else.
For Japanese speakers: There are users who make skits using singing synths, but a huge amount of them make videos using actual TTS. Videos are usually much longer than Western fans' videos (ex: Let's Plays, tutorials, cooking videos, multi-video skits). The Western fandom barely interacts with this content due to lack of subtitles, and barely knows it exists or how popular TTS characters are, let alone being able to remember the character names.
So I feel like if a person who ONLY speaks English is going to make a talkloid video with IA, they would use her singing software (ex: VOCALOID). A Japanese user would use her TTS. I would be very surprised if someone who can't speak Japanese bothered buying an expensive TTS IA voicebank for a few very short joke talkloid videos due to being unable to fully utilize the bank. If someone who can't speak Japanese buys her singing voice, they can also use it for covers, which is more bang for their buck because you can cover songs without being able to speak the language. In addition, CeVIO is not compatible with Kotonosync, so there is less appeal of jumping through hoops to make TTS IA sing because she already HAS singing banks.
(This is just my humble opinion.)