I think there's a shot. Currently we have violins, guitars, and pianos. With keyboards as an offshoot of pianos, same with electric guitar, and the organ. If you count the microphone for signing and comedy, using your voice as an instrument, you have 4 main categories.
We're still missing percussion and wind. The dj booth only sorta counts. So I do feel like they might bring in drums, some sort of wind instrument, and MAYBE a bass. Especially if they can do both like a larger string instrument like a cello, and then like an electric bass.
That way they could tie in several in game mechanics like clubs to make a band, or even use the club mechanic as a base for actual bands like the wolf pack or vampire family thing. And then how the HSY has after-school activities you could have school band. Just adding some wind and percussion instruments could help that a lot. So I think they could easily patch those in.
Plus with fairies being teased I absolutely wouldn't be surprised if they made it so that new instruments came with them. Not just magic, or perhaps them being tied to horses (whether in friendship or time of release), but like giving them more in the pack. Like enchanting with song, the power to have a sim dance until they die. Stuff like that.
So more instruments could be added there. Stylized ones in that pack, and then obviously base versions for everyone else of that nature. Like a fairy drum, but a basegame drum kit and toddler drums, and xylophone for kids or infants. An enchantress flute, and my first recorder, and then the flute you get in band in HSY as your sim tries to become the next Lizzo.
I think it would be rather interesting and quite possible for them to add more. I just don't think they'd add a ton. But they might in a few of the areas they haven't so far. And like we randomly got the organ, but after that only got guitars if we got anything, or more piano stuff. But if they're finally giving us new lifestates, we might get more stuff we hadn't before. I mean we just got a new lifestage and now have toys that make sounds. Who knows?
