Pearl: Most likely as it's a big map and she was meta before the buff.
Abyss: Another big map and I think her util is easier to get value with on this map. I find her in ranked quite easy to play. I just stun + suck when I hear or see Jett dash out and then suck and stun and peek and kill or tell my team to peek and kill. Getting onto site I would stun + sometimes suck the box and the other sides.
Ascent: Her + Sova finna go crazy. Also don't think one was that good on Ascent imo. I think this map Astra gets more value usually than an omen blind
Haven: This map is definitely gonna be a 50/50 pick. Omen is very good on this map but maybe some teams will opt for Astra instead.
Split: Another 50/50 map. I really like Omen on split as it provides great aggressiveness and his blind is really good but Astra can also be pretty good for some teams.
Rest of the maps I think Viper/Omen just clear.
Icebox = Viper
Sunset = Omen
Bind = Brim + Viper
I think Astra depends more on the playstyle of the team.
Teams like FNC like to play slow and gain map control with minimal util to make crazy execs with Astra is better at.
Teams like SEN love fast map control and love to hold it which Omen is better at doing but less strong execs.