Centralized exchanges and many platforms will put your account with a red flag if you log in it after a very long time of inactive. Especially if you log in your account on a new device, new IP address but if this activity is done by the real owner, no big issue to prove it with simple step.

Scam exchanges can use this reason to pull their scam KYC card and it's not true to generalize it for all exchanges.

If they sent you an email with a link to a website, to download their application, you should be careful and not click on it. That can be phishing links.

Want to download an exchange application?
You can get it at their website. Again, don't click on link in email. Find their website at Coinmarketcap.com, Coingecko.com and get links for downloading.