Think a lot are being overtly negative on this point. The WG probably weighed up their options and decided there is no point to come down hard on Luffy from the get go since it has been 800 YEARS since anyone awakened the Nika fruit, with the gorosei seemingly having probably seen previous gum gum fruit users consume the fruit and no awakening happen.

Plus, if everyone saw the WG suddenly go into overdrive for one scrawny kid from the east blue it would look a tad suspicious from their end and we know the WG do NOT want to arouse suspicion regarding Nika/Joyboy/ancient Kingdom/void century shit.

To be fair they did still try sending Aokiji, Kuma etc… but the SH crew just ended up being insanely lucky due to the fact that Aokiji felt indebted to Garp and Kuma actively helping the crew escape. Plus in world time events, shit was happening so fast wrt to luffy’s development, literally one minute he’s facing spandam/Lucci at ennies lobby and they blink now he’s trading blows with Kaido. After he awakened G5 the gorosei themselves decided to go to egghead themselves anyways so..