While Rick Gates might not have any evidence on 45* (at least at this report’s moment in time), he can confirm some other matters related to his time as deputy campaign chair.
Remember that he stayed on through the transition, albeit marginalized but still overlapping the RNC and the Trump campaign. Remember Pence chaired the transition, and some of Flynn’s crimes occurred during that period.
Even in the case of the RNC Ukraine plank, some related money must have moved considering Gates’s involvement with money laundering.
Gates joined Trump's presidential campaign in June 2016, when the candidate hired Manafort as its chairman. At the Republican National Convention the next month, Gates directly handled the campaign's operations as Manafort's top aide.
Perhaps the most controversial step taken by Trump's campaign at the convention concerned how the U.S. should deal with the tense relations between Russia and Ukraine, which repudiated Moscow in a 2014 revolt.
When a delegate proposed that the Republican platform call for "providing lethal defensive weapons'' to Ukraine's military in its struggle against Russian-backed armed forces, the Trump campaign defeated the effort. Instead of U.S. weaponry, the convention platform committee accepted the campaign's substitute language, which offered Ukraine "appropriate assistance.''