Are these Giant bikes fake?

The paint scheme looks like that of the 2009 Giant Defy Advanced 1 Check out https://www.bicyclebluebook.com/value-guide/product/3050124/ bikepedia.com and bicylebluebook.com have lots of info on bikes by year and model. Here's the 2010 Giant Defy 1, which again looks very similar, with a few minor differences in the paint scheme: https://www.bicyclebluebook.com/value-guide/product/19422/

I would say they (both posts) are most likely either being intentionally misleading or they don't actually know what kind of bike they have. Looking at their the 2016 Defy 1, it seems to be disk only, and be specced with 105 level components. Even going back to 2013 which is as far back as Giant's site seems to go back, it's still speced with 105 level components. As @Criggie mentioned in the comments, 9 speed Tiagra has been discontinued well before 2016.

However, it seems that even Giant's own site doesn't have their complete past catalog anymore, but this article seems to point towards it only being available in disc brake versions.

For 2016, the world’s largest bicycle manufacturer steps forward again, trickling down the disc brakes of the upper-tier models and merging them with the alloy frame that takes multiple design cues from the carbon models

It seems that by 2016, only the Sora level model, the Defy 3 (and the Defy 5 with Claris level components had rim brakes.

They are most likely not counterfeit bikes as it would be unlikely to put so much effort into a low-mid tier road bike, but it does seem they are both being represented as something they are not.

Thanks to the answer from @Armand, it looks a lot like the paint scheme of the models 2009/2010. Maybe the seller bought it from a shop, the shop genuinely sold it as a 2017 model, who knows.

Anyway, I would suggest you to stay away from buying such a bike unless provided with a receipt of the original transaction or a signed and verified agreement from the seller (something where you have ID's number and you can check it).

Counterfeit probably is not, dubious origin for sure it is, unless proven differently. See this unrelated but related to second-hand shopping question

In addition to the answers you already have, it sounds perfectly possible that the bike was stolen in the past, even if the person currently selling it is unaware and bought it in good faith.

You might want to check if your country operates anything like the UK's immobilise or smart water, both are schemes aimed at tracking and tracing stolen property.

I would say things like these are worth checking every time you look at a bike with anything less than complete sale-and-purchase history, as you might be doing a great favour to someone who once had their beloved bike nicked!