I believe you must have gotten all the balloon series before you start getting non-balloon furniture. I kept getting balloon items until I finally got a balloon vanity, then I started getting other furniture every other balloon.
I've had a few non balloon items - round carpet, kick scooter (which I think is a new item, so they are possible as well) and then a load of balloon furniture again.
So its definitely intermittent.
The dog lamp is now called poodle dog lamp, wish they had just left it short, but hardly matters either way.
Subjective but I seem to hear more balloons - not that there are more in total, just that they seem to spawn near to me, rather than being a random spawn- I have my doubts as to this, but .... well I'm not complaining as I've always popped the balloons (for the dog lamp to use in feng shui).
If you wanted any more incentive to pop balloons, they can also drop the new update items. So far I've gotten the desktop mic, autograph cards, bamboo fence, kick scooter, and cypress plant.