Can I get preventative blepharoplasty for hooded eyes?

Without a photograph, your question is theoretical and therefore difficult to answer. Many East Asian eyes have a natural degree of ptosis with more hood that is ideal. I would not recommend surgery now for theoretical future concerns. If you have a concern now, that is one thing. Don't get surgery that you don't need because you are concerned about what might happen in the future.

For significant improvement, hooded eyelids require surgery if there is enough skin. For nonsurgical treatments: Radiofrequency (Thermage or Venus Legacy/Viva), injectable fillers, and a Botox brow lift can help contour the eyebrows and lift the eyelid skin. I recommend getting a formal evaluation with an experienced cosmetic dermatologist. Best, Dr. Emer.

Aesthetic blepharoplasty is performed when patients develop bothersome hooding. I advised against it until you are ready.

Upper blepharoplasty can be done very naturally and it won't affect the normal aging process of the eyelid. See an expert.