This is not the same, and can cause other problems "down stream". If for example you use that alias field in a EVAL you can not do that anymore.  
The below (super simplified) example will not work anymore: 
 _raw data1: "2018-12-06 15:54:00 Account_Name=arnold sid=123 message=bla"   
_raw data2: "2018-12-06 15:54:00 user=arnold sid=123 message=bla"  
 FIELDALIAS-user = user AS Account_Name  
EVAL-userid = case(isnotnull(user),user, isnotnull(sid),sid) 
 in data1 you will miss the Account_Name field even though it is in the data, this cannot be solved with evals in this manner:  
EVAL-user = coalesce(Account_Name, user)  
EVAL-userid = case(isnotnull(user),user, isnotnull(sid),sid) 
 Because according to the props.conf spec file:  
* When multiple EVAL-* statements are specified, they behave as if they are run in parallel, rather than in any particular sequence.  
* For example say you have two statements: EVAL-x = y*2 and EVAL-y=100. In this case, "x" will be assigned the original value of "y * 2," not the value of "y" after it is set to 100. 
 So in my opinion this is a major breaking change in the way 7.2.x works, and there is no mentioning of it in any doc (spec file/release notes/known issues/.....) 
						
					
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