Sure ! Thank you for opening a space to share our experience with LibreOffice opening and saving native XLS files.
Our company (about 50 employees) make light use of spreadsheets. No heavy files, no fancy formatting and graphics, no intense sharing of files (for this we use google docs suite); In this context, we had not problems having a mixed environment (LibreOffice not always updated and MS Office ranging from 2010 to 2016), so I see no problems doing that.
The source of information for many of this spreadsheets is our ERP program that export data in CSV format that is filtered and summarized using spreadsheet usual functions (FILTER, SUM, PROCV, etc)
Data supposed to be shared with co-workers are uploaded to Google Docs OR its is shared in XLS format in a read-only shared folder (just a few people has write permission on it) and in this case, there is no risk of data corruption.
I appreciate your concern, but it was not a problem for us in the past years.