Mailcow writes that stands with Ukraine. Telegram is russian service, made by russian and who-knows what is supported and developed by russians. During the latest round of its so called financing (bonds issuing) a lot of money came from russia related companies. Telegram is mostly proprietary software in contrast to Mailcow; its business model is ambiguity. Even just “using” telegram helps it to stay on top and to assist its end beneficiaries to persuade their hidden unclear goals.
In the case, why not to switch to more open, democratic messenger, e.g., Matrix, XMPP, name it?