I'm a member of the events team so I have some perspective on this though am not part of the poltergeist suggestion reviewal process. We've already been working on this year's rewards for the past month and you'll have to wait and see for the specifics of how they're obtained etc, but I can confirm that there will definitely be some rewards similar to the ones you've mentioned coming up for this years Christmas Event! (They will be unique and not repeated collectables from previous years because having these collectables as limited-edition is what gives them value / motivates players that got all the previous year's rewards to play the next event- so you'll have to buy that specific reindeer plushie off of someone that played that specific Christmas Event)
Though this is a bit aside from the original suggestion, Nyn as you may have noticed with Halloween, items that compete with the store (hat, broom, wand appearances etc) have been moved to the store instead of continuing to be released as event items. Therefore, we will definitely be making lots more of the types of collectables Malfoyzz mentioned as well as new models that don't compete with store items, such as the bat handbag from the Halloween event. (Also the enthusiasm for ice skating has been noted!)