As already written in the comments, there is no reason to add que there.

However, this extra que does not make any difference to the pronunciation if, as is expected, the final c of avec blends into the start of que. That might explain why the writer didn’t notice the mistake if they went over it too quickly.

Note that in the past, avec even used to be written avecque(s) (from Latin apud hoc).

Later, the final que was eroded, and even the final -c became silent, so at that stage a common pronunciation was avé. This pronunciation can still be heard in Provence.

The final -c was restored in modern French pronunciation.

Note: Deepl translation was not bad, here is a small correction:

Some of you were thrilled to watch Penny Oleksiak’s gang pick up medals by the handful at the pool, others shed tears with Antoine Valois-Fortier when leaving his tatami with him, while others blasted¹ with pride as they crossed the finish line with Andre de Grasse on the Olympic Stadium track.

The author suggests that the viewers share the emotions of the athletes by being virtually at their side on the sports fields.

References: Wiktionnaire, Littré, TLFi, Académie, Académie

¹ _{Lambie’s kind contribution}

The Original Machine Translation:

Some of you were thrilled to watch Penny Oleksiak’s gang pick up medals by the handful at the pool, others shed tears with Antoine Valois-Fortier as he left his tatami, while others exploded with pride as they crossed the finish line with Andre de Grasse on the Olympic Stadium track.

of this French Canadian spoken text:

Certains d’entre vous ont vibré en regardant la bande à Penny Oleksiak ramasser les médailles à la poignée à la piscine, d’autres ont versé des larmes avec qu’Antoine Valois-Fortier [a mistake, could be a reversal] en quittant son tatami, alors que d’autres ont explosé de fierté en franchissant le fil d’arrivée avec Andre de Grasse sur la piste du stade olympique.

If this is spoken French, the ne could have been left out by a fast speaker or the automatic closed caption program could have missed it:

Certains d’entre vous ont vibré en regardant la bande à Penny Oleksiak ramasser les médailles à la poignée à la piscine, d’autres **[n’]**ont versé des larmes qu’avec Antoine Valois-Fortier en quittant son tatami, alors que d’autres ont explosé de fierté en franchissant le fil d’arrivée avec Andre de Grasse sur la piste du stade olympique.

Edited translation:
Some of you were thrilled when watching Penny Oleksiak’s gang scoop up medals by the handful at the pool, while others had only tears for Antoine Valois-Fortier as he was leaving the mat, while others still were bursting with pride as they saw Andre de Grasse crossing the finish line on the Olympic Stadium track.

Please note: usually in French you get NE verb QUE, but sometimes the ne is left out in fast speech.

The very first verb implies spectators, so I have kept that idea while keeping the spectators off the mat and away from the finish line. As this is probably spoken language, there are some odd things in the flow of the French which would be true in any language coming from a commentator. One cleans up as one goes along translating in written form in cases like these.

The idea I think with the Fortier thing is this: les spectateurs ne pouvaient que verser des larmes en le voyant quitter son tatami.

In other words, the spectators were thrilled for the swimmers, could only cry for Fortier and again were very happy with/for André de Grasse.