Maybe we could say that this is the (perfect) time for gambling addicts to come out from addiction but we don't know if they have that thought.
If they have no choice to play then maybe they can get out but if they are a online gamblers, the game continues as there as still a lot of gambling sites that are open and offering variety of games.
I'm not sure if they are taking such action or maybe they will find a way to continue their pleasure in gambling. It is not the pandemic or lockdown that could make them stop but it is all about how much willing they are coz if they want to get out from that addiction, they should have to do it at any time.
Maybe they can stop if their family is infected with the virus, as a person we always prioritize our family over anything, unless we have no love for them. Gambling gives pleasure but when you are addicted, you can't feel it, you think it's a need and you let gambling control you instead of the opposite.