Would you want an expansion focused on kids and toddlers?

I was going to choose kits but think a better chance at freeing babies in a gamepack. And adding group activities (play) for kids. They do imo have a lot of stuff already for them but I feel they need more interactions together.

I am a family player and would love more options and gameplay for them (i.e. prom nights, sleepovers, and (gasp) even a new life stage), but these can be accomplished with a game pack. I feel an expansion pack would feel too empty, though I would think a stuff pack to be better suited.

Depends on the actual content tho.

I voted game pack.
More interactions and options need to be made as there's still not a lot for teens or kids to do.

I'd love teens to have better dating and networking options.

I'm glad kids will be able to help cook and garden but I'd like fun activities too.

I'd like toddlers to be able to 'draw on walls'.

For children:
1. Add more elementary school activities, such as school picnic/graduation trip/swimming lessons
2. Can join the school if the player is having Get To Work
3. Preteen stage
4. First love
5. Tutorial schools
6. Selling lemon juice on the street
7. More traits such as lost of milk teeth, adolescence, dislike opposite sex during the first half of childhood

For toddler
1. Can join daycare or kindergarten if the player is having Get To Work
2. Pain of growing teeth
3. Toddler can use normal swimming pool when they're having swim rings
4. Tricycle for toddler

Please I would adore this more so if it has more toddler beds, ones that are bunk beds would be adorable. Toddler swings! More equipment more activities like after school stuff

I don't play either enough to warrant an expansion (especially given they are only short portions of a sim's lifespan), but I also would hate to relegate any topic (unless it's mainly B/B-focused) to kits or stuff packs. Maxis is more likely to make the topic's gameplay interesting or in-depth in a gamepack, and were it to be an expansion, it would need to focus on more (such as teens, as has been stated).

I think all of the things you mentioned would work fine in a Gamepack focussed on Childhood. It should also include many more child-child and child-toddler interactions than we have now, like all the games that child sims in previous games could play (like Mary Mack, tag, cops and robbers, hide and seek, etc) and the teach a nursery rhyme interaction that existed between children and toddlers. (Actually, I think those social interactions should be added to the basegame, not come in a pack).

Any child centered GP should also include (as essential elements for me) the bake oven, the bake sale table and the lemonade stand for children, and the toy xylophone and (small) teddies for toddlers. I would even like to have the music boxes from Sims 3 back; they were very nice. Some new interactions and toys that we've never seen before might be nice to have too. I would certainly buy such a game pack in a quick minute.

But what I want most of all is a Generations-style Expansion pack which adds all kinds of content for the neglected life stages in the Sims 4 (babies, toddlers, children, teens, and elders). Preceding it should be a patch freeing the babies from their bassinets (as some have already suggested). It could include the activities and events for children that you mentioned but could also include teens in some of them, and add unique hobbies and events just for teens (proms, etc) and elders (bingo, bridge, etc) too.

It would also be nice to have some of Generations' other best features back: the stroller (for both babies and toddlers), the sleeping bag, the ability to make home movies and play them on the TV, the playpen and walker (store objects in the Sims 3), and/ or the baby swing and floor mat (store objects from the Sims 2), the bachelor/bachelorette party with an exotic dancer, baby showers, the elders' canes, the show family pictures animation (so cute) and of course teaching teens to drive. If they finally added the ability for kids to ride bikes into the game, they should also add the ability for older sims to teach them to ride a bike; toddlers could get tricycles.