Sure it is - Pep even rubbished these rumours earlier in the year. He's already demonstrated he honors contracts so isn't going anywhere, the management team are effectively made of individuals who have either worked extensively with Pep in the past or pursued him heavily to come to City, for years. Moreover, he just finished one season with no uncertainty looming which is often the reason for extensions
Only scenario where it makes any sense is perhaps Guardiola sees the project as requiring more time than he initially believed & hence the club wants to reinforce they are fully behind Pep. Strange nevertheless as there does not seem to be a need to do this now