No. You must obtain a Windows 10 multi-language ISO separately.
No. Office 365/2021 has separate language packs. However, the system language influences Office's default selection. windows 11 iso multi language
Even with a multi-language ISO, some UI elements (like legacy Control Panel applets) may remain in the original language until you fully restart the system. Part 6: Supported Languages in Official Multi-Language ISOs Microsoft organizes languages into two tiers: Tier 1 (Fully localized – 38 languages): Arabic, Bulgarian, Chinese (Simplified & Traditional), Croatian, Czech, Danish, Dutch, English (US/UK), Estonian, Finnish, French, German, Greek, Hebrew, Hungarian, Indonesian, Italian, Japanese, Korean, Latvian, Lithuanian, Norwegian, Polish, Portuguese (Brazil/Portugal), Romanian, Russian, Serbian, Slovak, Slovenian, Spanish, Swedish, Thai, Turkish, Ukrainian, Vietnamese. Tier 2 (Limited LIPs – require base language): Over 80 languages including Basque, Catalan, Galician, Icelandic, Irish, Kazakh, Malay, Swahili, Uzbek, Welsh, etc. These are included in the VLSC multi-language ISO but may not appear in the retail ISO. Office 365/2021 has separate language packs