Spontaneous exchange of information

Hi everyone. Do you know how prevalent is spontaneous exchange of information between the countries?

Let's say you move permanently to the UK, become tax resident there and start paying taxes for your business/trading activity in the UK. Would the tax officer question whether or not you paid taxes in previous years for the same activity (before you became a tax resident in the UK) in your previous country (one country in Asia)? If so, how likely is it that they will send the information about your activity to your previous country of tax residence?

I have found this information about spontaneous exchange of information from UK tax internal manual:

Spontaneous exchange happens when an officer in one tax authority spots something that they believe to be foreseeably relevant to another tax authority, and gives it to their Competent Authority to send on.
If you find something in the course of enquiry, or during in a meeting, which indicates that there is a tax impact in another jurisdiction, you should consider passing the information on.

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In general do tax authorities care if you paid the taxes in previous countries?