Without any deeper invormation about ME4 and the intentions of the developers, any kind of opinion and suggestion would be REALLY vague.
That's why i stay with "could" and "would" and not "it will be like this"... or do you have a mole anywhere inside Bioware?
'think' does not = 'know'
In this case I use the definition of "to have or form in the mind as an idea, conception, etc. "
I have several things that I think the next game will be about and contain, and this is just one of the possibilities to me.
Source: my critical thinking. Looking at the past game content, its possible symbols and themes, the upcoming Bioware content, possible leaks, and possible rumors.
Of course I don't know what the next game will be. I could be entirely wrong. But saying 'think it will be' is often the same as going 'this could be'. I think it will be a cloudy day here outside, based on weather reports and the time of year, but I don't know it for certain. It could happen or it could not.
I'll turn off the snarky text tone now, sorry! It's not intended.