The IRS has not announced when e-filing of amended tax returns will be available.

Only this new release is available - https://www.irs.gov/newsroom/irs-announces-form-1040-x-electronic-filing-options-coming-this-summer-...

IRS started accepting electronic filing of 1040-X on August 17, 2020 but Turbo tax software has not been made available to file it electronically.  No idea when Turbo Tax will update to allow this.  I sent my amended return in in Mid April (16 weeks and counting) and still does not show as processed.  And this was just to change the fact that no one can claim me as a dependent.  IRS is sooooo backlogged its not funny.

@debalkris If you already mailed a 1040X, do not e-file another one even when e-filing for 1040X becomes available or it will just cause more confusion and delay.  TurboTax has not told us yet when e-filing for amended returns will be ready on this site.  Sorry, but you will simply have to wait for the IRS to process the amended return you mailed in.  It is taking longer than normal for them to process amended returns.  They are digging through 11 million pieces of mail that accumulated in trailers during the pandemic. Realistically, you should not count on getting your stimulus check this year if it is based on an amended return.  If you do not get it this year, you will be able to get it on your 2020 return when you file next year, provided you are not someone else's dependent for 2020.  If they somehow process your 1040X and send you a stimulus check this year, be pleasantly surprised.

Similar situation here. Sent my 1040X the first week of May, been 15 weeks now with no acknowledgement of receipt (https://www.irs.gov/filing/wheres-my-amended-return), and seems they completely disabled call-in contact. Can't tell if it's in their mail trailer or the USPS never delivered (shame on me no return receipt). Just got my first late notice. If they would simply acknowledge receipt that would help a lot, I am tempted to assume it's lost and efile a duplicate. If I could.......

Back to the original question - When will TurboTax upgrade TT Pro 2019 to include 1040X efile?

Yes, Turbotax will be updated. No, we don't know when.  And if you already filed on paper, you have to wait for that to be processed, there's no way to cancel it to e-file instead.