Twitter doesn't encrypt messages, so there is indeed no chance of that happening - after all the reasoning for this arrest is fundamentally inapplicable to Twitter.
It's however a very very very slippery slope to prosecute someone for providing the tools to hold encrypted communication, just because this is also used by criminals. A lot of privacy oriented services would probably have to exit France if this holds up
by default telegram doesn't encrypt anything. I'm not sure if you where implying that telegram had encryption and therefore hiding illicite activities.
The problems is the huge telegram channels spreading hacks and illicite tricks.
It's however a very very very slippery slope to prosecute someone for providing the tools to hold encrypted communication, just because this is also used by criminals. A lot of privacy oriented services would probably have to exit France if this holds up