Embraer wasn’t looking for partnership but sale. Had the deal gone through the E2 series would have become a Boeing brand to compete with Airbus 220 the former C series. This would have shifted Embraer back to smaller biz jets and tactical lines. However the Issues with the Max series of 737 and convid 19 air industry hold has pretty much put Boeing in a no go zone. The Max is now being used as a regulatory testing lab with every part being placed under the microscope and new qualifications being drafted off of it that will be applied to every new aircraft that enters production and sales.Embraer - not worth the hassle. US will roll over Brazil like an ant on the sidewalk.
Example : Last December, Trump slapped tariff on Brazil steel and aluminum when China bought soy bean from Brazil instead the US and Brazil capitulated to get the tariff rescinded.
Taking it in reverse order,Candidate for a partner.
Rolls Royce, Safran or Airbus - sure.
Partnering with Airbus is questionable as the ARJ21 vs Airbus 220, the Comac 919 vs A320Neo and CRIAC A330Neo. I know auto makers do partner with the indigenous makers in China and many of the local Chinese brands bread and butter Are rebadged and indigenous models built on import power trains. Yet that’s a harder sell when the buyers are state owned and the builder is state owned and where with cars you can sell by the thousands it’s hundreds
The Smaller regional jets are the hot sellers these days. Tying to partner Airbus with Comac well having the inside track of the ARJ 21 to the Chinese market isn’t an easy sale.
Safran doesn’t have an engine option if the US decides to impose trade restrictions. The LEAP series is a 50/50 joint between Safran and GE. If GE is out so is LEAP. Unless the French buy out GE or they design a totally new engine.
Rolls Royce is of course British as such they are able to sell freely, unless the UK decides to enact restrictions of her own.