j"19HxigV4QyBv3tHpQVcUEQyq1pzZVdoAutLImmutable means it can't be mutated - can't be changed. It doesn't mean it can't be muted, or filtered. Same laws that apply to Twitter will apply to Twetch.
text/plaintext twetch_twtext_1562236448351.txt|"1PuQa7K62MiKCtssSLKy1kh56WWU7MtUR5SET twdata_jsonnullurlnullcommentnullmb_user74reply@2b3052351ea5ad0e82c010f94bdcc769cf463f7642288ad40d109ac39c6b52e2typereply timestamp1171206440593701apptwetch|"15PciHG22SNLQJXMoSUaWVi7WSqc7hCfva
BITCOIN_ECDSA"1AKHViYgBGbmxi8qiJkNvoHNeDu9m3MfPE##computed_sig##
https://whatsonchain.com/tx/3ec2ea305a3020a18a2f51264296a816e0e214a852c176f218ce92a545722412