While Daniels may have to sign for the LLE as a last restort, Danny might be trying to keep on somewhat good terms with Daniel's agent. I'm sure the LLE is not desireable, and was used as a "sign of commitment," so I wouldn't be surprised if Danny is doing his end and making every effort to give Indiana more.
Fringe players like Walker & Giddens (who is 25+ years old already?) will rarely have an impact on the team. They're not in the short term planning, and as a previous poster commented, it is very easy to replace a decent wingman in this league.
Also, isn't there a financial advantage for the Celtics to send Walker over since they won't have to pay his salary? I'm sure it's not a big salary, but dropping any salary when you're in luxury tax is a benefit.
Either way all of this will barely impact the team so long as Celts get Daniels.