Let's take a look Fukkatsu No F's poster showing Freeza for the first time:

There are three main takeaways from this poster:
1. Freeza is not transformed yet. Meaning that this was a prelude to his new form.
2. Freeza's arms, legs and tail had Gold spots before we even got the trailer showing his Golden Freeza Form. These were subtle hints at his new form.
3. Vegeta has a blue lightning that makes part of his hair look blue which was a hint to SSBlue.
And now, let's take a look at Goku's new form:

What I take from this:
1. Goku, just like Freeza, is not transformed yet. This is a Prelude to the new form in my opinion.
2. Subtle Red marks over Goku's back, arms and shoulders. Such marks are more distinguishable by looking at his left arm. Something similar to what they did with Freeza's gold spots.
3. If you take a look at the Flame-like ki that's covering Goku, it seems there's a figure inside. I can't tell what it is. Not sure if it's an Oozaru or a Dragon or just my brain messing with me.

Conclusion: Although is a long shot and I am aware that there's a full front shot of Goku in this state, I think this is just him getting ready to transform. Based on those red marks, I think Goku is going to transform into Dragon Ball Super's equivalent of the SSJ4.
Thoughts?