As always German laws are a mess and they want to bend freedom.
Anyway change to signal it was always the superior option.
Given that MobileCoin is a new way for them to fund their operations without a trace, it's sound very attractive for these extremists to stay underground without exposing themselves due to Signal's E2EE than Telegram. Also, no censorship on Signal, so it is a free for all without the consequences.
Best part is, MobileCoin is just about to be a great pump and dump ponzi once they officially launch on Signal. Great value proposition for criminals and speculators.
Signal groups are poor at that. The work required to encrypt messages increases with group members. People don't want to show their phone numbers in large public groups, and Signal also lacks the group admin/moderation options necessary to handle many hundreds or thousands of members.
Atilla Hildemann used his channel as a one-to-many broadcast. He doesn't want a group chat.
Telegram is probably the only tech in world, which has this unique mechanism of communicating. Cloud backup, groups/channels, anonymous usernames, e2e encryption feature (1 to 1, not by default), censorship resistance more than other messaging/social media companies, all bundled together.