Enable Office 365 Tenant Sign-Up to provide selectable option for default SPO language
When creating a new Office 365 Tenant, your SPO default language is determined typically by the language of the marketing page you signed up from - e.g. https://products.office.com/en-gb/business/compare-more-office-365-for-business-plans or https://products.office.com/de-DE/business/compare-more-office-365-for-business-plans?omkt=de-DE the latter being German and former English.
This may mean that the default language provided for SPO is not what you intended it to be, e.g. English instead of French or German instead of English. Some organizations want to have a default language that suits their business needs.
There is no easy way to change this to your language of choice once your tenant is created. Also, there is no clarification of what language SPO is going to use when you sign-up, you are not provided with an option of what language you prefer. The latter would be a useful addition to the sign-up process and make it clear what language will be used or provide an option to choose an alternative.
Ian Caldwell commented
+1 - we ended up with Swedish. Not very helpful for our employees in the US, Thailand, Kenya or Colombia. There needs to be a way to change the tenant SPO localeid - in our case, we have 1053 and need 1033.