The phrase "undoubtedly joining" is correct and usable in written English.
You can use it to emphasize the certainty of a certain action, such as entering a club or group. For example, "She was undoubtedly joining the book club to meet new people and learn more about literature".
He and his men will now undoubtedly join the OLF and fight the Ethiopian government.
It was clear, however, that both Mallory and Irvine had been involved in a serious fall that broke the rope which undoubtedly joined them.
In what will undoubtedly join the internet club of outlandish and awesome Bar Mitzvah invitations, YouTube user Mathias Schu uploaded a video that took things to the next level.
Although the asymmetrical towers at the center of the plaza are unfinished, the project has already been awarded the Leadership in Energy and Environmental Design LEEDD) Gold certificate by the United States Green Building Council and upon completion, will undoubtedly join the ranks of the world's greenest buildings. .
The nominees are a closely guarded secret but whoever wins – Pope Francis is currently the bookies' favourite – will undoubtedly be an impressive sort, joining the ranks of Mother Teresa, Nelson Mandela, Martin Luther King, Desmond Tutu, the Dalai Lama, Barack Obama and Aung San Suu Kyi.
Rio's Maracanã is the venue for an undoubtedly grandiose send-off, with Clare Balding, Adam Hills and Jonathan Edwards joining thousands of athletes.
Undoubtedly, we need more cases and more labs joining in this pursuit before we can begin to estimate the frequency of hybridization in cancer.
It undoubtedly encouraged others to join in the chaos.
There are undoubtedly many different features joined in any one of the proposals, and even a sequence of failures may not show where to place the blame.
Either of them could have chosen to chuck it all in and join the army - undoubtedly trickier than learning how to water ski.
