No it wasn't updated for the EIC. You mean you see a larger refund when you log into Turbo Tax or did the IRS send you more?
Did you enter any unemployment? There have been major IRS changes for that. If it is unemployment the IRS will automatically adjust your return. So you do not need to amend.
If you have unemployment you can exclude up to 10,200 if your income is under $150,000. Your unemployment compensation will be on Schedule 1 line 7. The exclusion will be on Schedule 1 Line 8 as a negative number. The result flows to Form 1040 Line 8.
If you already filed and didn't get the 10,200 unemployment exclusion you do not need to amend. The IRS will be adjusting it for you. See,
https://www.irs.gov/newsroom/irs-to-recalculate-taxes-on-unemployment-benefits-refunds-to-start-in-m...
