Russian media secondary source referenced in the OP: https://www.kommersant.ru/doc/8846793

The stated reason is that it is no longer economical to maintain the physical infrastructure for only telecommunications. This is likely objectively true, and both the Finnish and Russian sides of the business agree on that. As I understand, the same lines were used pre-2022 for exporting electricity into Finland from Russia. However, that year, the electricity was cut off by the Russians in the lead-up to Finland’s NATO application.

The part that is left out is that the cessation of electricity exports was not so unilateral. Russia claims that Finland had stopped paying for electricity. If that is the case, then the likely reason for the stopped payments is the EU and US sanctions against Russia. So, the whole situation — both stopping electricity imports and stopping telecommunications traffic — is the unilateral decision of Finland, not Russia, considered as a whole. But you will not find this direct explanation from Yle or BBC or any western media.