Not necessarily. They may simply know whatever is loose can be handled without a vaccine—and wanted to get something relatively harmless out there so they wouldn’t be forced by optics to go the mRNA route. It might be that Brazilian or other doctors or governments were about to reveal how limited its reported effectiveness.
Um, there are other techniques that aren’t full-traditional-killed-virus or mRNA. The Chinese did the former. The Russians, Johnson & Johnson, and AstraZenica all used the “deactivated carrier virus mocked up to look like COVID-19” method.