I wouldn't say they're exactly unstable; a new org for sure but they're in quite a few esports now and they got a ton of big sponsors (they got CocaCola this week for example) so its a steep upwards trajectory for them atm
It just depends on how much riot wants to gamble taking a rapidly growing org or if they'd rather take an org that's been established for longer
The main reason I see them taking the chance is that guilds been a staple of EMEA valorant, they've been there since the start and have been in tier 1 consistently, as well as owning a tier 1 female roster, so theyve shown investment