The Falcons, who finished bottom following the 22-game regular Premiership campaign, will only be relegated if the eventual Championship winners meet top-flight entry criteria.
Bristol were one of those clubs, but a 29-18 second leg semi-final victory over Cornish Pirates was not enough to keep them in title contention.
Pirates' 45-24 first-leg triumph underpinned an aggregate success of 63-53, and they will now meet London Welsh in the two-legged final on May 23 and 30.
The Pirates did not put themselves forward for the Rugby Football Union's Premiership entry audit, and neither did Bedford, who were edged out 30-27 by London Welsh over two legs.
Bedford won Sunday's second leg 24-17 at Old Deer Park, but they came up just short after losing the home tie 13-3.
The Richmond-based Exiles are adamant they will meet Premiership entry criteria, which they underlined through a statement released earlier this week by club chairman Bleddyn Phillips and the board of directors.
It is thought that they are considering a possible ground-share with League Two football club Oxford at the Kassam Stadium, although a move to Harlequins' Twickenham Stoop has also been mooted.
The RFU and Premiership Rugby intend clarifying the promotion situation ahead of the Championship final, yet Newcastle are still clinging to survival.
Dean Richards, whose three-year worldwide coaching ban expires this summer following his role in the Harlequins' Bloodgate saga, will take charge of the Falcons next season.
Despite beating fellow strugglers Wasps away from home last weekend, Newcastle still ended propping up the table by a point, and they will now hope that the Pirates emerge victorious after the final's second leg.
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Lions get ready for their matches with this green training jersey. It's what the players wear. Get in the Gear!
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The Lions are ready to get their Australia tour underway. They arrive in Perth on Monday.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.