not at all
just cause the attack was offscreen doesnt mean gojo was caught offguard by it
1. the spatial slash requires a charge up , so it isnt instant
gojo DEF knew something was coming at him when sukuna was abt to attack him
2. characters can differ between what type of slash is coming
kashimo knew that the slash sukuna just did was the one which cut reality , so they arent the same
3. we saw mahoraga throw a slash just like sukuna did
so gojo must know how it feels when a world slash gets charged up and comes at him
all sukuna did was copy the stuff mahoraga performed
u can easily see the slashes being similar
gojo would have felt the same world slash coming at him from sukuna
even mahoraga's world slash was very similar to sukuna's dismantle
4. gojo has all the abilities to feel that world slash being charged
there is quite literally no reason for the world slash to be a surprise attack,
gojo has the ability to see a powerful move coming at him and determine which type of move it is
so stop talking like gojo was caught surprised or something , he doesnt even talk anything abt that in the afterlife
he straight up admitted sukuna is stronger than him due to what happened at the end
ikr mr " they will kill each other in the fight "
try to debunk my points above instead of creating imaginary scenarios like gojo being surprised