This is NOT happening (yet). If they will be acquired it wouldn't be announced at TGS because the fact they would be teasing this on twitter would scream unprofessionalism and a headache for stockholders.
And if this does happen further down the line, that's a coffin for Sony. Sega has played a tremendous role on PlayStation platforms and has that identity. That would be such a huge lose for Sony I don't think they could do anything realistically that would make up for this. Thus, Sony must've not allow this to happen.
In fact, Sony themselves should probably purchase sega as japanese people would at least respect it, they don't respect companies like microsoft xbox.
But I fear that whenever Sony sticks there nose now will be met with a bidding war that they clearly can't win. So either way, Sony is fucked.
They need to get at least Kojima and Bluepoint. Publishers are honestly out of the question. The end is nigh