Update 2:
after replacing the display (twice) & replacing the logic board, the rattling and noise is still there.
Apple told me this time that they cannot do anything about it and that it's "within the specs" and normal.(so why they changed display and logic board if it's normal and why it only happens to some new Macbook Pros and 12" MacBooks?)
I asked if there is anyway of knowing which new MBP / 12" MB has the issue and they had no idea.
we tried 2 2017 MBP without touchbar and 1 2017 12" MB at store and I couldn't hear any rattle, altho the technician told me 3 12" models they have inside for repair do make the rattling noise.
since there is no solution and because Apple simply no longer have a good quality, problem-free laptop I've decided to sell the flawed MB and considering switching back to Windows after 10 years of Mac.
there are some really interesting Windows machines out there : Huawei Matebook X,new Dell XPS 13,Surface Pro and Galaxy Book.all high quality machines within same price range and without such ridiculous flaws.