User check - new, removed, changed?

Hi

I'm starting to make a dashboard where we want to be able to check for changes in our user database - which we load on a monthly basis with new entries per month, something akin to this:

Now in Excel (where we do this right now) we just have a tab for each period and run simple VLOOKUPs to do this. But we want to automate it in PowerBI and create a dashboard with statistics and lists of who is affected by each change.

I want to do three things - all is done with checking within 1 month. So we don't want to compare data further back/forward. 
1. Added ID - not present in previous month (unless earliest month is minimum value, just to stop getting thousands of adds first month we include in dataset). ID 4 in example above, should be given a field "Added" = Yes for the period 2020-02-01.

2. Removed ID - not present in next month (unless month being looked at is maximum month). ID 2 is removed in 2020-02-01 so should get a "Removed" field in period 2020-01-01, since it looks forward one month and it has data for 2020-02-01 and beyond. Unless there is an easy way to automatically insert a new entry for the month after it was removed in a dashboard? 

3. Changed value - we use this for several fields, but understanding it for a single one is what I need. If Deptartment has changed from previous to next month, add a field "ChangedDept" = Yes. In example over ID 1 changed Department in 2020-02-01 and should get "Yes" in the field for that period, but not 2020-03-01 since it's not a change from the previous month. 

EDIT: Ok, been finding ways to do this on my own but now it's more if those solutions are the most effective:

1. I added a PreviousMOnth and NextMonth calculated field - it gives what they suggest (DATEADD +1/-1,MONTH). 
2. I then run IF with calculations to get the various data in new calculated fields:

Added = 
IF (min(IDs[Date])=IDs[Date],"",if(
    CALCULATE(
    min(IDs[ID]),
    filter (
        all(IDs),
        IDs[Date]=EARLIER(IDs[PreviousMonth])
        && IDs[ID]=earlier(IDs[ID])
    ))=IDs[ID],"","Added"))

Is it possible to move the Next/PreviousMonths into that expression? I tried just pasting them in but EARLIER doesn't work with on-the-fly calculations (i.e. EARLIER(DATEADD(IDs[DATE],-1,MONTH)) didn't work ).