Tbh, I do agree that it was foreshadowed to some extent.
There are lots of evidences regarding it so people who deny this aren't being honest.
But oda executions regarding it is bad.
Let me tell you why
1) Like haki, oda didn't care to explain awakening. Generally author explains power before giving it to MC but here he totally dodged it.
Also, When awakening was first introduced then we came to know that user is able to affect his surroundings.
But nika is totally different.
2)We learnt that awakening happens when one masters it's df.
Sure one can argue Luffy mastered his df evident from G4 versions but nowhere resurrection was mentioned.
We don't know how Luffy after dying resurrects with awakening.
3)World Government knew that Luffy has nika. Sure no one awakened it centuries but just based on their talk it seems they definitely want to take that fruit.
Yet, they didn't do shit about it until Luffy faced kaido and oda was about to drop awakening.
So, it does come across as he definitely had idea about nika but he didn't plan how to execute the idea properly