Using "Replace variable with..." does not mark a blueprint as needing compilation

Using "Replace variable with..." does not mark a blueprint as needing compilation.

Reproduced in 4.9.2 binary, 4.10.1 binary, and Main 4.12 (CL 2813214). This is not a regression; the same bug appears in 4.9.2 (reported in 4.10.1).

1. Open any project
2. Create a new Actor Blueprint
3. Drop the Actor Blueprint into the level
4. Add two Float variables with default value 0.0, Var1 and Var2
5. Begin Play > Set Var1 (12.0) > Print String (Var2>string)
6. Right click the Set Var1 > Replace Var1 variable with Var2
7. DO NOT COMPILE
8. PIE

Result:
The BP is not marked as needing compilation after Replace variable with, and the Print String prints 0.0 (Var1)

Expected:
The BP requires compilation, after which Print String prints 12.0