stolen iphone / removed device

my iphone was stolen but i had not activated "find my device"

i rushed to computer within few minutes and saw an option to remove device from icloud which seemed to offer security

after this i have seen advice not to do this and to report through settings (on computer). i immediately changed icloud password and two step verification number

assuming the phone auto locked after 60 seconds (I chased for 30 seconds) should my data be secure ?