I agree, and on that I see little point on returning for the first moments of the outbreak or much of the story before their meeting. It isn't like she will meet with her mother, and she lived with her. So I see little need to dewelve much on her past.

Ellie's mother would be a major indicator of Ellie's potential mindset. It would give the 'hate' theme credence, breadth and context. 

Doesn't she already know what happened to her mother?

And she already carry a lot of hatred inside her.

But that's just an arbitrary mechanic that tells us nothing of the person. You must have heard the old saying 'the apple doesn't fall far from the tree'. I wouldn't in any way use that to actually judge a person but in a narrative sense it's used as a trick to bridge the gap between how a person once behaved to how we're expected to believe they're behaving now. The 'layers' or personal traits are what makes the narrative realistic. Just as personal traits of Ellie could be mirrored in her mother (let's say a love of creatures), traits of Ellie's mother could be mirrored in Ellie, and as an audience we'd buy into it because we're used to that narrative trick. 

"Ellie's never done this before, although I can see how she's very much like her mother." People then accept the jump without so much exposition. We think: 'It's always been in her' because we assume 'the apple doesn't fall far from the tree'. 

I particularly doesn't see much value in it since she is already pretty mature and have experienced enough to have her actions being her own and not effects of what her mother experienced or done... but sure they may do it. I just see no point in call it part 2 and take much time in the past.

because it will release on the ps5

It will initially be exclusive to ps4 and ps4 pro. Now of course a masterpiece like this series will get ported to the ps5 after it launches. You would have to hate money not to.

The more I watch that trailer and read what Druckmann said, the more I think we're being lead astray. He's said the theme is 'hate' while the last game was 'love'. The first game's theme was far more nuanced than 'love' and I think the only reason he's boiled it down to that is so he can mislead us by suggesting the second game's theme is 'hate', also a rather flat theme. In this trailer we see what appears to be an integral antagonist getting killed. Why would they show us an integral character getting killed in a trailer? Even if she hasn't got a huge role to play, it's bound to spoil some aspects of the narrative.

I'm not buying any of this.

yeah a goty remastered with all the dlcs would be awesome in 4k 60 fps

I'm pretty sure he said the theme of the first game was "Hope", not "Love". Anyway you're not the first person I've seen misquote him on that and likely won't be the last.

On another note, as far as I know Ellie's mom died when Ellie was a Baby so say like 5 years into the infection breakout. That doesn't seem like enough time for a religious cult to gain any ground. So I'm not buying this scene being taking place before Ellie was even born.