The Complex Text Layout (CTL) mode is enabled by default. The CTL mode is used by languages like Hebrew, Thai, Arabic, and Hindi. Those unfamiliar with the CTL mode can find explanations here and here from their documentation.
As explained in this Christmas day commit, "Some of these UI elements are required for editing RTL [right to left] documents and it makes no sense to hide them by default and then rely on some heuristic to guess if the user might need them (which fails half of the time). Hopefully this will also help not overlooking these elements in the new UI experiments (like how the sidebar missed the paragraph direction settings for few releases making it rather useless for RTL documents). I suppose we should do the same for “Asian” support, but I don’t know much about how this is used so will not touch it for now."
So this should be good news for LibreOffice users using one of the CTL languages with a better out-of-the-box experience for this open-source office suite and also ensures developers working on the new user-interface changes don't forget about the CTL mode.