I have to get a new PC by the start of next year. Till then, i am getting this on PS4. But later, i will definitely get this on GOG.

Hence, i wanted to ask if there's any preorder bonus on GOG because i don't miss out even if i won't be able to install the game from GOG till i get the new PC.

No preorder bonuses but you get additional stuff when ordering from GoG in general:
https://items.gog.com/not_a_cp/ENG_product-page-addons_v2.png

Also not a bonus per se, but if you want to support CD Projekt RED directly there's also this:
https://images.gog-statics.com/5643a7c831df452d29005caeca24c28cdbfaa6fbea5a9556b147ee26d325fa70_bg_crop_1920x655.jpg

Warm fuzzy feelings.

According to the front page, the most prominent reason to preorder on GOG is

"100% of your money goes to CD Projekt Group"

I expect the fuzzy feeling sensation only increases if you give the money months before any expectation of reward.


For a serious answer, the preorder bonus expired six months ago

Pre-order Cyberpunk 2077 on GOG.COM before September 13th 10 PM UTC and get a 40% off discount code for Displate metal posters, including their latest official Cyberpunk 2077 line.

The reward for giving all your money to CDPG a year before the games release is to spend even more money on Cyberpunk 2077 merchandise.

Physical stores may also have exclusive preorder bonuses, that someone might consider worthwhile, but it comes at the cost of those warm fuzzy feelings.

So, i won't miss out on any in game related content if i buy on GOG after release?

Sadly they are at times.

Crimson Curse: Expansion Trailer and Pre-order Pack But in answer to the original question: There are no announced in-game exclusives. If there is, it will certainly hit the front page, so if you are paranoid - check back regularly.