If you do NOT get out of her, you will receive part of her plagues. If this is near to happening, and if God reveals to his people before he acts, then it would be important to understand this would it not? Not that your condemned if you don't just from that scripture Rev 18:4, but God is intending to do something and as a kindness giving a warning.
Consider back in Ancient Jerusalem's time......they were given a warning of what was about to happen to Jersusalem and how to escape it.
Now, if this is something you would like to know. What is your current understanding of it? Is it false religion? Is it the WT? WHO? AND if you identify who, then what exactly are the 'plagues' you will share if you remained or won't have to share if you get out?
(Sometimes just trying to seek one answer, will lead you on the path to many answers)