Yes, apparently "sentence" is only used in French law to mean two things: (1) sentences handed down in criminal cases (same meaning as in English but not relevant here, since arbitration only exists in civil cases, not criminal); and (2) arbitral decisions. Since this article is talking about arbitration, by definition it's not talking about criminal cases, so the meaning of sentence is #2: arbitral decisions.
The contrast is therefore between arbitral decisions and court decisions. And the author seems to be using "sentences" (which is synonymous with "jugement arbitral") in order to be able to make that distinction; if the author referred to "jugements arbitraux" and "jugements du tribunal" or something like that, it would make for longer, less elegant sentences. Using sentence to mean arbitral decisions and jugement to mean court decisions lets the author make the distinction clearly without resorting to unnecessarily long turns of phrase.
"En procédure civile, la 'sentence' est le nom donné aux décisions rendues par des arbitres. Mais on peut aussi dire 'jugement arbitral.'"
https://www.dictionnaire-juridique.com/definition/sentence-d...
